the Abstract Book - Donostia International Physics

The workshop is dedicated to Prof. Hiromu Ueba
and to all of his contributions to these fields.
18:10
17:30
16:50
15:40
15:00
13-15
12:10
11:30
10:20
9:40
9:00
Lunch
M. Blanco-Rey
Coffee
Various Manipulations
Chair: M. Alducin
Inelastic spectroscopy with sub-atomic resolution
K. Morgenstern
Revealing molecular dynamics through scanning
noise microscopy and spectroscopy
R. Möller
Dynamics at Surfaces V
Chair: M. Alducin
Poster session
Molecular junctions: A nonequilibrium atomic limit
M. Galperin
T. Todorov
Interatomic forces under current
B.N.J Persson
Tribology at the atomistic level
Workshop dinner
Starting at 21.00
Spin, Forces and Photons in Molecular Tunneling
Junctions
J.I. Pascual
Controlled switching molecule-electrode interfaces Electron-Phonon coupling and molecular dynamics Subsurface Hydrogen and Deuterium Manipulation
in the presence of current
by Ballistic Electrons
M. Brandbyge
Coffee
Electronic currents + dynamics
Chair: K. Morgenstern
Coffee
Dynamics at Surfaces I
Chair: M. Kawai
H. Okuyama
W. Hofer
Theory of scanning tunneling microsopy: studying
dynamic processes
M. Wolf
Probing the transient electronic structure in surface
femtochemistry
K. H. Ernst
Chirality in molecular recognition and dynamics at
surfaces
E. Chulkov
Relativistic effects in surface electronic structure of
solids: Bychkov-Rashba systems and topological
insulators
Lunch
Dynamics at Surfaces III
Chair: K. Morgenstern
Opening session
Chair: M. Kawai
R. Temirov
Imaging and control of large organic molecules
within a scanning probe microscopy junction
R. Robles
Site- and orbital-dependent charge and spin
manipulation in supported transition metal
phthalocyanines
R. Palmer
Atomic manipulation by electron injection
T. Komeda
Manipulation of Spin in Double Decker
Phthalocyanine Molecule
Coffee
Dynamics at Surfaces IV
Chair: M.-L. Bocquet
J.-P. Gauyacq
Excitation of magnetic adsorbates by tunnelling
electrons: atoms and chains
M. Persson
Charging and Bond formation of Adsorbates on
Ultrathin, Insulating Films Supported by a Metal
Substrate
Coffee
Spin Manipulation I
Chair: A. Garcia-Lekue
R. Berndt
Manipulation of the spin and charge states of
adsorbed molecules
A. Groß
Molecule-surface interactions at complex metal-gas
and metal-liquid interfaces studied by ab initio
molecular dynamics simulations
M. Kawai
Local Symmetry Rules Spin Ground State: FePc on
Au(111)
M. Alducin
Does N2 adsorption increase on strained Fe
monolayers?
Wednesday
Spin Manipulation II
Chair: M.-L. Bocquet
Tuesday
Dynamics at Surfaces II
Chair: A. Garcia-Lekue
Arrival / registration
Monday
Closing + Lunch
Vibrationally mediated single molecule reactions in
real space and in real time
H. Ueba
A multi-state single-molecule switch actuated by
rotation of an encapsulated cluster within a
fullerene cage
H. Petek
Understanding Inelastic Electron Spectroscopy of
single adsorbates on metal surfaces : start « small
», finish « big »
Coffee
Dynamics at Surfaces VI
Chair: M. Paulsson
M.-L. Bocquet
Mechanisms of rotation of a single acetylene
molecule on Cu(001) by tunneling electrons in STM
S. Tikhodeev
Azobenzene-Based Single-Molecule Junctions:
Charge Transport Mechanism and IETS
Fingerprints
A. García-Lekue
IETS
Chair: M. Paulsson
Thursday
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Much interest has been generated by the bottom-up approach in which
nanostructures are built from their atomic constituents in an atom-by-atom fashion.
Regardless of the feasibility of this approach to become technologically interesting, a
great deal of attention has been devoted to the study of the dynamics of a singleatom or single-molecule adsorbate on surfaces. Different types of excitations have
been explored to obtain controlled dynamics, e.g., electronic and photonic excitations
are at the heart of the main atom-manipulation techniques. The experimental
developments over the last 20 years have yielded a wealth of data on singlemolecule dynamical processes, with unprecedented accuracy and control, opening
the venue to new strategies in the study of surface science as well as in new ways of
creating technology at the atomic scale. The recent experimental developments
allows for quantitative theoretical calculations. Indeed, the controlled dynamics of a
few atoms is easier to computationally simulate than for macroscopic ensembles
where statistical factors have to be considered together with many other effects that
make difficult a detail comparison with experiments. Hence, the quest for quantitative
evaluation of atomic dynamical processes is a reality that can be presently
confronted with accurate experiments. This is an opportunity that allows many
advances for the development of theory and of computational tools. In this way, a
new field of quantitative simulation and understanding for surface dynamics and
controlled reactions is emerging. It is then very interesting to bring together
theoreticians working in this field, in particular given that no major conference or
workshop exists that allows them to exchange ideas and create a field that is thriving
on the experimental side. At the same time, a theory and simulation workshop would
certainly profit from discussions with leading experimentalists that can direct the
attention and work of the several groups involved in the understanding and prediction
of single-atom manipulation strategies. This is the framework of the present
workshop, where the main theoretical and experimental groups in the field will be
invited speakers.
Let us also mention that some of the key leaders of the field are becoming senior
researchers, and we would like to devote this workshop to their inspiring leadership.
In particular, this workshop is hopefully our humble tribute to honour the lifelong work
of Prof. Hiromu Ueba who recently retired from Toyama University and joined the
research group of Prof. Maki Kawai in Tokyo University.
Thomas Frederiksen, DIPC, San Sebastián, Spain
Nicolás Lorente, CIN2, Barcelona, Spain
Magnus Paulsson, Linnaeus University, Sweden
C
ARRIVAL IN BILBAO AIRPORT: There is a direct bus operating between Bilbao Airport
(outside the arrival hall) and San Sebastian (Plaza de Pio XII). The service departs from the
airport every day, once an hour, between 7:45 am and 11:45 pm (on Saturdays, Sundays
and public holidays there is an additional service at 6:45 am), see http://www.pesa.net.
Tickets are 16.50 EUR. From the bus terminal in San Sebastian there is just a 10 min. taxi
ride to Hotel NH Aranzazu (cost ~10 EUR). A taxi ride all the way to Hotel NH Aranzazu or
the DIPC is about a 1h15min drive (100 km).
ARRIVAL IN SAN SEBASTIAN AIRPORT: The public transportation from the airport is
described here: http://www.aena-aeropuertos.es/csee/Satellite/Aeropuerto-SanSebastian/en/Page/1237554585679//Public-transport.html. A taxi ride to Hotel NH Aranzazu
or the DIPC should be of the order 30 EUR.
ARRIVAL IN BIARRITZ: The public transportation to/from San Sebastian is described here:
http://en.biarritz.aeroport.fr/access-car-parks/biarritz-airport-access.html. A taxi ride to Hotel
NH Aranzazu or the DIPC is about a 45 min drive (50 km).
Addresses:
Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal, 4
Hotels:
NH Aranzazu, Vitoria-Gasteiz Kalea, 1
Colegio Mayor Olarain, Avenida Ondarreta 24
Workshop dinner:
Restaurant Branka, Paseo Eduardo Chillida, 13
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Mohamed Ahmed
Maite Alducin
Andrés Arnau
Andres Ayuela
Richard Berndt
María Blanco-Rey
Marie-Laure Bocquet
Mads Brandbyge
Eugene Chulkov
Martina Corso
Karl-Heinz Ernst
Giuseppe Foti
Thomas Frederiksen
Michael Galperin
Aran Garcia-Lekue
Jean-Pierre Gauyacq
Axel Gross
Alexander Gustafsson
Werner Hofer
Maki Kawai
Georgy Kichin
Tadahiro Komeda
Takashi Kumagai
Jingcheng Li
Nicolás Lorente
Reinhard Maurer
Rolf Möller
Karina Morgenstern
Hiroshi Okuyama
Richard Palmer
Chiara Panosetti
Jose-Ignacio Pascual
Magnus Paulsson
Bo Persson
Mats Persson
Hrvoje Petek
Roberto Robles
Yulia Shchadilova
Ruslan Temirov
Sergei Tikhodeev
Tchavdar Todorov
Hiromu Ueba
Martin Wolf
Majzik Zsolt
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Spin-orbit interaction plays significant role in electronic processes in solids, and is, in
particular, important for the description of electronic structure of surfaces where translation
symmetry along the z-direction (perpendicular to the surface) is broken and spin degeneracy
is lifted. This leads to intriguing effects and promising applications in spintronics. Here I
analyse two groups of systems where spin-orbit interaction underlies unusual spin behavior
in surface electronic states, namely, Bychkov-Rashba systems and topological insulators.
Special attention is devoted to the latter class of materials with emphasis on the current
theoretical and experimental status of research and future.
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Fritz Haber Institute of the MPG, Dept. of Physical Chemistry, 14195 Berlin, Germany
Electronic non-adiabatic processes at surfaces are frequently discussed in the context of the
interaction of adsorbates with metal surfaces leading to phenomena like interfacial charge
transfer, chemicurrents or electron induced reactions. In particular, femtosecond laser
excitation of metal surfaces results in a highly non-equilibrium electron distribution, which
may eventually induce chemical reactions of adsorbed molecules. The dynamics of such
processes occur on ultrafast (typically femto- to picosecond) timescales. These processes
are accompanied by pronounced changes of the electronic structure which can be studied
directly in the time domain by appropriate spectroscopic techniques.
In this talk, I will introduce basic aspects of surface femtochemistry using the example of CO
oxidation and desorption on Ru(001) and then discuss how in very recent experiments the
corresponding transient electronic structure changes can be probed using an x-ray freeelectron laser (LCLS). By employing time-resolved resonant inelastic x-ray scattering
(trRIXS) the electronic structure of CO molecules on Ru(001) is probed as their
chemisorption state changes after excitation with a fs laser pulse. The observed transient
changes are consistent with a pronounced weakening of the CO chemisorption bond,
whereby a large fraction of these molecules are transiently trapped in a precursor state on ps
timescales prior to desorption.
Acknowledgements: This work was performed in collaboration with Mischa Bonn, Daniel
Denzler, Gerhard Ertl, Christian Hess, Stefan Funk, Christian Frischkorn, Steffen Wagner,
(femtochemistry); Martina Dell’Angela, Toyli Anniyev, Martin Beye, Ryan Coffee, Alexander
Foehlisch, Jorgen Gladh, Tetsuo Katayama, Sarp Kaya, Oleg Krupin, Andreas Mojenhog,
Anders Nilsson, Dennis Nordlund, Jens Norskov, Hirohito Ogasawara, Henrik Öberg, Henrik
Öström, Lars Pettersson, William F Schlotter, Jonas A Sellberg, Florian Sorgenfrei, Joshua
Turner, Wilfried Wurth (trRIXS @ LCLS);
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Department of Chemistry, Graduate School of Science, Kyoto University, Japan
[email protected]
Single-molecule switch that controls electric current between two macroscopic electrodes is
a key device component in future molecular electronics. It is essential to precisely control the
molecule-electrode interface that plays a critical role in electron transport through the
junction. Here we present controlled switching of a molecule-electrode interface in a
scanning tunneling microscope (STM) junction.
A phenoxy molecule bonded to the Cu(110) substrate is lifted up to make a contact with an
STM tip while it is anchored to the surface via a chalcogen atom, forming a molecular
junction across the two electrodes. The retract of the tip removes the contact with the
molecule, leaving it in the original position on the Cu substrate; thus the molecular junction is
reversibly formed and removed by controlled switching of the tip-molecule interface. The
reversible control of the junction in a well-defined environment enables us to precisely
investigate the conductance through the molecule, including the dependence on the
intermolecular coupling.
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I will show how molecular dynamics calculations can be used to obtain information about
tribological processes at the atomistic level. I first discuss dry contact mechanics, the origin
of friction and how to reduce friction (superlubricity). Next I discuss lubricated contacts and
show how fluid sqeeze-out occur at the atomistic level. Finally I discuss sliding of confined
polymer films.
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1
Institut für Experimentalphysik, Freie Universität Berlin, Germany
Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
3
Center of Material Physics, 20018 Donostia-San Sebastián, Spain
4
CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
2
Noncontact atomic force microscopy (nc-AFM), operated in frequency modulation mode, has
been the subject of extraordinary advances lately. For the first time single-electron charge
sensitivity was achieved [1] and the complete chemical structure of different molecules was
mapped with unprecedented atomic resolution [2]. Such measurements are possible by
detecting short-range bonding interactions between the foremost atom of a tip at the end of a
force-cantilever and the atoms at the surface. The short-range interaction regime can be
probed with a qPlus force sensor where one prong of a stiff quartz tuning fork is fixed to a
rigid support and the other bearing an STM tip is free to oscillate above the sample surface
[3]. Combined STM and AFM measurements can be performed in parallel so that the
properties of the delocalized electrons measured by STM are directly compared to the
localized chemical bonds probed by AFM.
In this poster we will review different approaches to probe forces at the nanoscale using a
combined nc-AFM/STM operating at 5K and in UHV, like probing the strength of
intermolecular (non-covalent) bonding, or mapping electrostatic forces. For the first, we use a
CO functionalized STM tip and an acetylene (C2H2) molecule adsorbed on Cu(111) to probe
site specific interactions between the two molecules. We find that the two molecules show
attractive interactions with maximum energy of ~70 meV. Simultaneous measurements of
frequency shift and conductance allow us to determine that for non-chemical interactions the
bond is formed before the electrical contact, contrary to the obvious case of metal or covalent
bonds.
The AFM cantilever besides its capability to detect forces can also function as a charge
sensor. The discrimination of different charge states of atoms and molecules can be directly
probed by means of local contact potential difference measurements [1], the so-called Kelvin
probe force microscopy (KPFM). We combined work-function and spectroscopy
measurements taken with the AFM and STM respectively on charge transfer complexes [4]
to provide a picture describing how much charge is involved, how it is localized in molecular
species and how it can be changed by applying electrostatic potential fields.
References
[1] L. Gross, F. Mohn, P. Liljeroth, J. Repp, F. J. Giessibl, G. Meyer, Science 324, 1428
(2009).
[2] L. Gross, F. Mohn, N. Moll, P. Liljeroth, G. Meyer, Science 325, 1110 (2009).
[3] F. J. Giessibl, App. Phys. Lett. 76, 1470 (2000).
[4] I. Fernández-Torrente, D. Kreikemeyer-Lorenzo, A. Strózecka, K. J. Franke, J. I. Pascual,
Phys. Rev. Lett. 108, 036801 (2012).
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1
Centro de Física de Materiales, Centro Mixto CSIC-UPV, Paseo Manuel de Lardizabal 5, Donostia-San
2
Sebastián, Spain Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, Donostia-San
3
4
Sebastián, Spain Department of Chemistry, University of Warwick, Gibbet Hill, Coventry, CV4 7AL. Depto. de
5
Física de Materiales UPV/EHU, Facultad de Química, Apdo. 1072, Donostia-San Sebastián, Spain
IKERBASQUE, Basque Foundation for Science, E-48011, Bilbao, Spain *[email protected]
Alkane chains ending with thiols or amines have been always considered a benchmark
systems for studies in the field of molecular electronics [1, 2] since they can be easily
functionalized and they form stable and well defined contact to gold electrodes. More
recently very high conductance values have been experimentally achieved starting from
trimethyl tin (SnMe3)-terminated molecules [3, 4]. In general, one of the main tasks once the
junction is physically realized is to verify the real compositional structure of the molecular
junction. Recently Cheng et al. [4] demonstrated that trimethyl tin-functionalized alkanes,
after loosing the Sn-(CH3)3 group, can form a direct Au-C bond with the metallic surface. In
that condition it was possible to achieve a conductance about 100 times larger than
analogous alkane based molecular junctions with other anchoring groups. Here we propose
an additional way to verify experimentally the nature of metal/molecule bonding. Inelastic
Electron Tunneling Spectroscopy (IETS) allows a unique compositional and structural
characterization of nanojunctions since it gives the vibrational fingerprint of molecular
adsorbates. So, comparing the IETS of (SnMe3)-terminated chains and that one of alkane
directly bonded to gold surface could allow an unambiguous characterization of
metal/molecule bonding since the two molecules give qualitatively different spectra. We
performed first principles calculation of the IETS of (SnMe2)-terminated hexane (C6Sn) and
of the same molecule but directly bonded to the gold surface through a covalent Au-C bond
(C6Au) and for different electrodes separations in a regime of elastic deformation. In Fig. 1 a)
and b) are shown the C6Au and C6Sn geometries respectively in the less stretched
configurations. Structural relaxation of all geometries was done with the DFT code Siesta [5]
while for the calculation of phonon modes and IETS the Inelastica package [6, 7] was used.
For both kind of molecules the IETS present the typical peaks of alkane chains.
Nevertheless, in the case of (SnMe2)-terminated hexane, at low energies the CH3 groups
give a strong inelastic signal which is not present in the case of the pure hexane chain with
direct Au-C bond [Fig. 1 c)]. This peak allows to easily distinguish the two types of molecule
and verify the presence of a direct bond of alkane with gold surface.
Figure 1
a) C6Au and b) C6Sn
geometries in the less
stretched configuration.
In c) is shown the low
energy part of the IETS
for the two geometries.
Thick line represents the
signal at negative bias.
At 90 meV the methyl
groups give a strong signal (red curve) which is not present in the case of C6Au.
References
[1] Y. Kim, T. J. Hellmuth, M. Burkle, F. Pauly, and E. Scheer, ACS Nano, 5 (2011) 4104.
[2] J. Zhou, C. Guo, and B. Xu, Journal of Physics: Condensed Matter, 16 (2012) 164209.
[3] W. Chen, J. R. Widawsky, H. Vázquez, S. T. Schneeabeli, M. S. Hybertsen, R. Breslow,
and L. Venkataraman, Journal of the American Chemical Society, 43 (2012) 17160.
[4] Z.-L. Cheng, R. Skouta, H. Vazquez, J. R. Widawsky, S. Schneebeli, W. Chen, M. S.
Hybertsen, R. Breslow, and L. Venkataraman, Nat Nano, 6 (2011) 353.
[5] J. M. Soler, E. Artacho, J. D. Gale, A. García, J. Junquera, P. Ordejón and D. SánchezPortal, Journal of Physics: Condensed Matter 11, 2745 (2002).
[6] T. Frederiksen, M. Paulsson, M. Brandbyge, and A.-P. Jauho, Phys. Rev. B, 20 205413
(2007).
[7] sourceforge.net/projects/inelastica
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[email protected], Linnaeus University, Växjö, Sweden
The hydrogen atom of an adsorbed hydroxyl (OH) exhibits fast back and forth flipping
between two equivalent configurations on a Cu-(110) surface at T = 6 K [1]. We have
calculated the relaxed geometries and reaction barrier using the SIESTA DFT code, where
the barrier is found from NEB-calculations to be ∼ 150 − 200 meV. The reaction is therefore
highly unlikely at 6 K, which suggests that excitations by tunnelling electrons and quantum
tunnelling are required to understand the reaction.
To theoretically describe the reaction phenomena we are developing a method based on the
T-matrix in the impulsive approximation to describe transitions be- tween vibrational states.
The approximation goes beyond the harmonic approx- imation in that the potential energy
surface for the vibrations is included to all orders. This opens up the possibility to understand
energy transfer between dif- ferent vibrational coordinates. The method should also be
extendable to DFT calculations.

H
O
Cu
References
[1] T. Kumagai, M. Kaizu, H. Okuyama, S. Hatta, T. Aruga, I. Hamada and Y. Morikawa,
Phys. Rev. B. 79 035423 (2009)
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1
Peter Grünberg Institute (PGI-3),Forschungszentrum Jülich, Germany
2
JARA-Fundamentals of Future Information Technology, Germany
[email protected]
In our contribution we report a new way to investigate the surface that can be done by STM
tip decorated with H2 (D2). Exciting H2 (D2) with inelastically tunneling electrons we are able
to expel it from the junction. Measuring and plotting the inelastic excitation energy along the
surface we obtain the information related to the surface adsorption potential with respect to
H2 (D2) [1,2]. Using a simple force-field model we attempt to recover the local adsorption
potential of the surface on the basis of the experimental data. Using same model we are able
to describe the features in the images that previously were suggested to be related to the
hydrogen bonds [3,4].
[1] R. Temirov et al. New J. Phys. 2008, 10, 053012
[2] C. Weiss et al. Phys. Rev. Lett. 2010, 105, 086103
[3] C. Weiss et al. J. Am. Chem. Soc. 2010, 132, 11865
[4] G. Kichin et al, J Am. Chem. Soc., 2011, 133, 16847
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1Fritz-Haber Institute, 2Kyoto University, 3Tohoku University, 4Donostia International
Physics Center, 5Toyama University *[email protected]
H-bond dynamics play crucial roles in diverse chemical and biological processes. Due to its
vital importance there have been numerous experimental and theoretical efforts for the full
understanding. Especially, H-bond dynamics in water have been ever-present questions in
physical chemistry and still remain poorly understood at the single molecule level in
heterogeneous systems like water-solid interfaces. Water-metal interface is one of the most
common interfaces on the earth and related with several industrial topics, i.e., corrosion,
heterogeneous catalysis, electrode reaction, and fuel cells. We have developed a novel
approach to study H-bond dynamics within water-based model systems on metal surfaces
using the scanning tunneling microscopy [1].
I will show the H-bond rearrangement within a water dimer [2] and H-atom relay reactions
within water-hydroxyl complexes [3] on a Cu(110) surface. Such model systems are
assembled by the molecular manipulation and selective dissociation of individual water
molecules with the STM. The two molecules in a water dimer exchange their roles as
hydrogen-bond donor and acceptor via hydrogen-bond rearrangement on the surface at 6 K.
The interchange rate is ~60 times higher for (H2O)2 than for (D2O)2, suggesting that
quantum tunneling is involved in the process. The interchange rate is enhanced upon
excitation of the intermolecular mode that correlates with the reaction coordinate. In waterhydroxyl complexes sequential H-atom relay reactions between water and hydroxyl are
controlled by STM. The experimental findings are rationalized by ab initio calculations for
adsorption geometry, active vibrational modes and reaction pathway, to reach a detailed
microscopic picture of the elementary processes.
References:
[1] T. Kumagai, “Visualization of H-Bond Dynamics, Springer 2012.
[2] T. Kumagai et al. Physical Review Letters 100, 166101 (2008).
[3] T. Kumagai et al.Nature materials, 11, 167 (2012).
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Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin,
Germany
2
CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
3
Departamento de Química Física, Facultad de Ciencias, Universidad de Zaragoza, 50009
Spain
Light emission from a scanning tunneling microscope junction has proven to be a versatile
experimental tool for investigating the optical and electronic properties with sub-nanometer
resolution. Until now, metal surfaces, metallic nanostructures, semiconductors, atoms and
molecules on metallic surfaces have been studied by STM-Light emission (STM-LE). Light
emitted from direct optical transitions of tunneling electrons in the junction contains rich
information about electronic systems. The optical spectra can reveal an energy resolved
picture of dipole active inelastic transitions during tunneling. Here we show our STM-LE
results obtained on different nanoscale systems: i) a bare Cu (100) surface, where twodimensional image states play a role in radiative electron transition, ii) copper nitride
nanodots grown on a Cu (110) surface, where a set of localized states mediate multi-color
light emission , and iii) one-dimensional molecular polymers, where coupling between
tunneling electrons and molecular vibration is uncovered, and the induced molecular heating
is studied.
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Lehrstuhl für Theoretische Chemie, Technische Universität München
Stabilizing molecules at solid surfaces and switching them reversibly between defined states
would be a key component of a future molecular nanotechnology. Recent experiments
indeed revealed such a photo-induced mechanism for tetr.- tert-butyl functionalized
azobenzene (TBA) at Au(111), while light induced iso- merization of pure azobenzene on
coinage metals was not achieved to this day. Adressing this suggestion with dispersion
corrected density functional theory, we investigate both prerequisistes to switching, namely,
the ground state stability of the two isomers as well as the existence of an efficient excited
state mechanism. Studying the groundstate energetics we find that metal surface adsorption
strongly reduces the barrier separating the two minima while at the same time destabilizing
the metastable state, leading to an effective loss of bistability for azobenzenes on Ag(111)[1].
Using a density-functional theory based Delta Self-Consistent Field approach we establish a
semi-quantitative account of excited state energetics in order to investigate the second
prerequisiste. The corresponding energetics suggest state renormalization due to interaction
with the image-charge, but in principle still allow dynamics following the gasphase
mechanisms. A detailed investigation will necessitate non-adiabatic dynamics simulations
that account for the metal bandstructure induced lifetime reduction.
[1] Maurer, R.; Reuter, K., Angew. Chem. Int. Ed. 51, 12009-12011 (2012).
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1
Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU),
Paseo Manuel de Lardizábal 5, 20018, Donostia-San Sebastián, Spain
2
Institut des Sciences Moléculaires, UMR 5255 CNRS- Université Bordeaux 1,
351 Cours de la Libération, 33405 Talence Cedex, France
3
CONICET and Centro Atómico Bariloche (CNEA),
Av. Bustillo 95500, 8400 S.C. de Bariloche, Argentina
4
Donostia International Physics Center DIPC,
Paseo Manuel de Lardizábal 4, 20018, Donostia-San Sebastián, Spain
The interaction of nitrogen with metal surfaces has been one of the most popular topics of
research in surface science for the last decades. This is due in part to the industrial
importance of ammonia synthesis, typically obtained from nitrogen and hydrogen catalyzed
over iron-based compounds. The rate limiting step in ammonia synthesis is the adsorption
and dissociation of nitrogen on the catalyst surface. In Fe surfaces, the reactivity of the
process depends on the face, the Fe(111) and Fe(211) surfaces being the most reactive
ones.
Although Fe(111) is the most reactive iron face for N2 dissociation, the dynamics of such
process has not been analyzed in detail. In this work we present exhaustive calculations of
the interaction of nitrogen atoms and molecules with the Fe(111) surface. These calculations
set the basis for subsequent analysis of the N2 dissociation dynamics.
We perform Density functional Theory spin-polarized calculations using VASP code. We first
study the relaxation of the Fe(111) surface, which was a matter of controversy in the past.
From here, we calculate the interaction energy of nitrogen atoms and molecules when
approaching the Fe(111) surface. Our results show the preferred adsorption paths and sites
for nitrogen adsorption, as well as the adsorption energies. We finally discuss the dynamics
of the dissociation process and make the link with the high reactivity properties of the
surface.
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Surface Science Research Centre, Dept. of Chemistry, University of Liverpool, L69 3BX,
Liverpool, UK
An overview on surface reactivity of halo-compounds on metal and semiconductor surfaces
will be presented, focusing on three systems whose characterization was carried out in our
group. We have been investigating the adsorption and reactivity of unsubstituted and
substituted hydrocarbons on Si(001) and Cu(110) surfaces using Grimme's vdW-corrected
DFT, CI-NEB and STM simulations. J. Polanyi's group at University of Toronto found that 1chloropentane forms asymmetric (A) and symmetric (S) pairs on Si(100)-2×1 with different
curvature of one pentane tail. This renders the rate of thermal reaction of A much greater
than S in chlorinating room-temperature silicon. The energy threshold for electron-induced
reaction is also different. We have used Density Functional Theory and Nudged Elastic Band
tools to explain the features of this system. Second, we have computationally modeled the
adsorption of 1,3-diiodobenzene (m-DIB) on Cu(110) by means of Density Functional Theory
including Grimme's van der Waals interaction correction. We have compared the adsorption
energies and structures of 23 possible configurations of the physisorbed molecule.
Furthermore, we have simulated STM images for the four most stable configurations using
the Tersoff-Hamann approach at different bias voltages. We find that all the adsorption
orientations have comparable energy and we discuss the relative probabilities of
experimental observation. We find that the adsorption induces small distortions in the
molecular structure of the adsorbate and in some cases an adsorption-induced symmetry
breakdown occurs. Since the studied systems provide a means to surface functionalization
via site-specific imprinting of single atoms, we also propose a model for Cu nanoclusters on
Cu(110) supported by one or two chemisorbed S (or Cl) atoms.
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1A. M. Prokhorov General Physical Institute, Russian Academy of Science, Moscow,
Russia 2Division of Nanotechnology and New Functional Material Science, Graduate School
of Science and Engineering, University of Toyama, Toyama, 930-8555 Japan 3School of
Computer Science, Physics and Mathematics, Linnaeus University, 391 82 Kalmar, Sweden
The physical model to describe the acetylene rotation on Cu(001) surface by STM [1] is
proposed. We identify three important contributions to the rotation rate and derive the
functional dependencies that cor- respond to each of the processes. These are: (A) the direct
over-barrier rotation excitation process due to an inelastic tunneling generation of the stretch
mode, (B) two-electron over-barrier rotation excitation pro- cess due to anharmonic
interaction of the CH stretch mode and the reaction coordinate mode, (C) inelastic electron
tunneling processes which involve a simultaneous generation of two coherent phonons.
We use the DFT analysis and the toy model consideration (“springs on rods”) to estimate the
anhar- monic coupling constants between the vibrational modes and consequently identify
the precursor of rota- tion of C2H2 on Cu(001) surface. We derive an effective model and
apply nonequilibrium Keldysh-Greens functions technique to describe the inelastic electron
scattering, and Pauli master equation for rotational mode ladder climbing. This allows us to
obtain functional dependencies of the reaction rates underlying process (B).
We also discuss the probability rate of the simultaneous generation of two coherent phonons
(C). The analysis of this mechanism using the Keldysh-Greens functions shows that the total
coherent phonon exci- tation rate takes the form of a single-phonon excitation rate, where a
single vibrational frequency is replaced by the sum of two vibrational frequencies. This allows
us to attribute the lower threshold voltage for rotation at ∼ 240 meV to this process.
[1] B. C. Stipe, M. A. Rezaei, W. Ho, S. Gao, M. Persson, and B. I. Lundqvist, Phys. Rev.
Lett. 78, 4410 (1997).
∗ [email protected]
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1 Centro de Física de Materiales CSIC-UPV/EHU, San Sebastián, Spain
2 Donostia International Physics Center DIPC, San Sebastián, Spain 3 Departamento de
Física de Materiales UPV/EHU, San Sebastián, Spain
*E-mail: [email protected]
In general, the open metal faces of a crystal are more reactive that the close packed faces.
In the case of transition metals, this has been sometimes rationalized within the so-called dband model [1]. This model states that the closeness of the center of the d-band to the Fermi
level causes an increase of chemisorption energies and a reduction of dissociation barriers
for activated systems. These ideas stimulated an increasing interest in exploring the
possibilities of surface strain as a promising tool to control the reactivity of different chemical
species. In this context, K. Homann and co-workers reported that the inertness of Fe(110)
towards N2 adsorption disappears on thin Fe layers grown on W(110) [2].
Motivated by this experimental data, we have studied the adsorption dynamics of N2 on a
pseudomorphically grown monolayer of Fe on W(110). Classical molecular dynamics
calculations within the frozen and oscillating (Generalized Langevin Oscillator model) surface
approximations are performed on top of a six-dimensional potential energy surface
calculated with density functional theory. The characteristics of the adiabatic PES, as well as
the results of the dynamics will be compared with those obtained in our recent studies of N2
adsorption and dissociation on the clean Fe(110) [3]. We will show that molecular adsorption
is clearly improved on the pseudomorphic Fe monolayer as a consequence of the
modifications introduced on the adsorption wells.
[1] B. Hammer and J. K. Nørskov, Surf. Sci. 343, 211 (1995)
[2] K. Homann, H. Kuhlenbeck, and H.-J. Freund, Sur. Sci. 327, 216 (1995)
[3] I. Goikoetxea, M. Alducin, R. Diez-Muiño, and J.I. Juaristi, Phys. Chem. Chem. Phys.14,
7471 (2012)
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Institute of Theoretical Chemistry, Ulm University, 89069 Ulm/Germany
Due to the increase in computer power and the development of efficient algorithms complex
structures and processes at surface can nowadays be studied from first principles, i.e.,
without invoking any empirical parameters. In particular, ab initio molecular dynamics (AIMD)
simulations have become possible in which a sufficient number of trajectories can be
computed to obtain statistically significant results [1,2]. It is important to note that the
uncertainty in the sticking probabilities derived from AIMD simulations does not depend on
the complexity of the considered system, but only on the number of calculated trajectories.
Thus AIMD simulations can address the dynamics in complex molecule-surface systems as
long as only a limited number of trajectories is required to obtain statistically meaningful
results.
In this contribution, I will present some examples of recent AIMD studies of complex systems.
I will address the adsorption and absorption of hydrogen on precovered surfaces. I will
particularly focus on the role of co-adsorbates in hydrogen subsurface penetration [3,4]. It will
furthermore be demonstrated that AIMD simulations can be used as an unbiased tool to
identify unexpected reaction mechanisms [3]. Furthermore, the role of steps in the
dissociative adsorption of oxygen on platinum will be elucidated. AIMD simulations represent
a versatile tool that can also be used to study processes at solid-liquid interfaces, as will be
shown for the hydrogen interaction with water-covered Pt(111) [5].
[1] Axel Groß and Arezoo Dianat, Phys. Rev. Lett. 98, 206107 (2007).
[2] Axel Groß, Phys. Rev. Lett. 103, 246101 (2009).
[3] S. Sakong, C. Mosch, A. Lozano, H.F. Busnengo, and A. Groß, ChemPhysChem 13,
3467 (2012).
[4] A. Groß, Surf. Sci. 608, 249 (2013).
[5] S. Schnur and A. Groß, Catal. Today 165, 129 (2011).
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Surface Science Research Centre, the University of Liverpool, Liverpool L69 3BX, UK
The ability to characterise and manipulate single atoms and molecules on ultrathin, insulating
films by scanning probe techniques has opened up a new frontier in atomic scale science. A
most interesting aspect of these systems is the decoupling of the electronic states of the
adsorbates from the metal substrate, which still allows for characterisation and manipulation
by tunnelling electrons.
The description of the electronic and geometric structure and the dynamics of these systems
exhibiting multiple charge states is very challenging for theory [1]. Density functional theory
calculations are in many cases prohibitive because of the size of these systems and the
delocalization error in current exchange-correlation functionals. In this presentation, we
present a new, simplified DFT scheme in which the metallic support is replaced by a perfect
conductor. This scheme circumvents these problems and allows us to treat various charge
states of adsorbates in a controllable way, together with a considerable reduction of the
computational effort. In particular, we are able to carry out ab-initio molecular dynamics on
an excited state potential energy surface. We will show some interesting applications of this
scheme to different charge states of metal adatoms and the dynamics of reversible bond
formation in a metallo-organic molecule [2,3].
[1] J. Repp, et al., Science 305, 493 (2004).
[2] F. Mohn et. al., Phys. Rev. Letter 105, 266102 (2010).
[3] T. Leoni, et al., Phys. Rev. Lett. 106, 216103 (2011).
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IMRAM, Tohoku University, [email protected], *Tohoku University Department of
Chemistry Graduate School of Science, ** CIN2, Spain
A research field of molecular spintronics attracts attentions. One of advantages of organic molecules
for the use in spintronics devices is that the spin and electronic states are strongly correlated with their
structures. By using ‘molecule switching’ with outer simulations like as current and light, a single spin
of a single molecule could be controlled. STM atom manipulation combined with atom-scale
spectroscopy should be the best instrumentation for the study of this field.
In this talk, we demonstrate spin detection and manipulation for a single molecule magnet (SMM),
bis(phthalocyaninato)lutetium(III) (LuPc2) which has double phthalocyanine (Pc) ligands. SMM is a
class of molecule in which a single molecule behaves as a magnet. We use the observation of Kondo
resonance for spin detection, which is a promising technique for the spin examination at surfaces and
interfaces. The Kondo effect, which occurs due to interactions between conduction electrons and a
localized spin, causes a change in conductance and has been observed mainly for metal and
semiconductor. Recently, it was also demonstrated that a pure organic radical spin can form Kondo
resonance on the Au(111) surface [1,2].
In Fig. 1, we demonstrated spin control of TbPc2 molecule by changing the azimuthal rotational angle
of the double Pc planes. The rotation was realized by applying a pulse bias to the molecule in which
o
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the TbPc2 molecule could switch between the stable q=45 and 30 rotational states in a reversal
manner. Accompanying the rotation, we can see on/off of the spin state by monitoring the Kondo state
(Fig. 1(c)). The change was caused by energy-shifts of the HOMO and SOMO states with the rotation
angle [3]. Figure 2 shows the variation of the Kondo state with the presence of Cs atom at the center
of the YPc2 molecule. With the electron donation from the Cs atom to the YPc2 molecule, we consider
that the unoccupied p orbital is filled and the p-radical spin is annihilated, which is followed by the
disappearance of the Kondo state [4].
[1] J. Liu et al. J. Am. Chem. Soc. 135 (2013) 651. [2] T. Komeda et al., ACS Nano 7 (2013) 1092. [3]
T. Komeda et al., Nat Commun 2 (2011)217. [4] R. Robles et al., Nano Lett. 12 (2012) 3609.
Fig.1 (a) Schematics of rotation of upper Pc ligand of TbPc2 by pulse application. (b) STM images for
o
o
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q=45 and 30 (c) Kondo peak variation with rotation from q=45 to 30 .
Fig.2. (a) STM manipulation of Cs/YPc2 (monolayer film) by pulse application. (letters T U) (b,c)
Kondo peak variation with distance from Cs atom.
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Centre d’Investigacions en Nanociència i Nanotecnologia, CIN2 (CSIC-ICN), UAB Campus,
E-08193 Barcelona, Spain E-mail: [email protected]
Advances in the development of molecular devices depend on the ability to control the
charge and spin of single individual molecules at the interface with a metal. Chemical doping
is one promising way of achieving this goal, but its usefulness depends on the ability to
understand the interplay between dopants, molecules and metallic surfaces. Here we use
scanning tunneling microscopy experiments and electronic structure calculations to
investigate the doping of supported transition- metal phthalocyanines by alkali atoms. We
study how charge transfer and spin moment change by hybridization with the surface, and as
a function of the occupancy of the 3d metal states. We show how the doping of individual
molecules by alkali atoms can be used to individually change the molecular charge and spin.
Furthermore, a scanning tunneling microscope can be used to place dopants on the
molecules with intraatomic resolution, allowing us to identify at least three stable adsorption
sites, and to manipulate the spin of an individual molecule in a controlled way without
resorting to the use of magnetic dopants. The comparison between conductance
measurements and density functional theory calculations allows us to gain deeper insight
into the doping mechanism.
[1] A. Mugarza et al, Nature Communications 2, 490 (2011).
[2] A. Mugarza et al, Physical Review B 85, 155437 (2012).
[3] C. Krull et al, Nature Materials 12, 337 (2013).
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1
Nanoscale Materials Science, Empa, Swiss Federal Laboratories for Materials Testing and
Research, Ueberlandstrasse 129, CH-8600 Dübendorf, Switzerland
2
IBM Almaden Research Center, 650 Harry Road, San Jose, CA-95120, USA
3
Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057 Zürich,
Switzerland
Molecular recognition among chiral molecules on surfaces is of paramount importance in
biomineralization, enantioselective heterogeneous catalysis, and for the resolution of chiral
molecules via crystallization or chromatography into their two mirror-image isomers
(enantiomers). Understanding the principles of molecular recognition in general, however, is
a difficult task and calls for investigation of appropriate model systems. One popular
approach is thereby studying intermolecular interactions on well defined solid surfaces. This
allows in particular the use of scanning tunneling microscopy (STM). We present an
elucidation of chiral recognition in self-assembled dimers of helical hydrocarbons at the
single molecule level. This includes lateral separation of the molecules that constitute a
dimer with a modified STM tip and the subsequent determination of their handedness with a
non-modified tip.
Fuelled translational motion along a surface by employing entirely synthetic systems remains
an extremely challenging goal and will be the key to the artificial molecular transporters that
offer fascinating opportunities for future technologies. We present here the design of an
artificial molecular four-wheel drive machine, based on chiral overcrowded systems, and
demonstrate that the concerted action of molecular rotary motors integrated in this system
can be used to induce translational motion across a metal surface
* Co authors of parts of the results presented in this talk: Tibor Kudernac, Manfred Parschau,
Nopporn Ruangsupapichat, Beatriz Macia, Nathalie Katsonis, Syuzanna R. Harutyunyan,
Ben L. Feringa (molecular motors), and Susanne Baumann, Johannes Seibel, Laura Zoppi,
Christopher Lutz, Andreas Heinrich (manipulation of dimers)
Financial support by the Swiss National Science Foundation and the Swiss Secretary for
Education and Research is gratefully acknowledged.
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Department of Chemistry/Physics, The University of Liverpool, Liverpool L69 3BX, UK
Dynamic processes in scanning tunneling microscopy (STM) are increasingly the focus of
cutting edge research due to their importance for energy conversion and reaction processes.
It is in principle possible to study these processes by a suitable adaptation of STM theory
and a step-by-step analysis of the processes themselves. I shall give several examples
where such a detailed analysis is indispensable for a comprehensive understanding, e.g. in
atomic switching and diffusion processes [1,2,3], in molecular growth processes on surfaces
[4], condensation reactions [5], and long range molecular propagation even on reactive
surfaces [6]. At the end of my talk I shall demonstrate that a careful statistical analysis in
combination with high-resolution STM can even lead to surprising new insights into
fundamental physics [7].
[1] WA Hofer et al., Nanotechnology 19, 305701 (2007)
[2] WA Hofer et al., Physical Review Letters 100, 026806 (2008)
[3] Y Wang et al., Journal of the American Chemical Society 131, 3639 (2009)
[4] KR Harikumar et al., Nature Nanotechnology 3, 222 (2008)
[5] KR Harikumar et al., Nature Chemistry 1, 716 (2009)
[6] KR Harikumar et al., Nature Chemistry 3, 400 (2011)
[7] WA Hofer, Frontiers of Physics 7, 218 (2012)
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Dept. of micro and nanotechnology, Tech. Univ. of Denmark (DTU), Denmark
The influence of an electronic current on atomic dynamics is an important and intriguing
problem in molecular electronics. We have developed an approach based on the semiclassical Langevin equation(SCLE) to investigate the excitation of atomic dynamics in a
nanoconductor in the presence of electrical current [1, 2, 3]. In the SCLE description the
nonequilibrium electronic environment is described like an effective "bath" influencing the
atomic dynamics causing fluctuations and dissipation. The SCLE approach allows us to
identify the forces acting on the atoms due to the electronic current. We show how the
current can cause several types of instabilities in a nanoconductor which ultimately can lead
to contact breakdown. These include run-away behavior due to excitation of "water-wheel"
modes [4, 2, 3], and amplification of the phonons for contacts driven by the non-equilibrium
electronic friction [5]. We also discuss how the electron-phonon coupling itself may change
significantly in the presence of current [6].
[1] M. Brandbyge and P. Hedegård. Phys. Rev. Lett., 72, 2919, 1994.
[2] Jing Tao Lü, M. Brandbyge, and P. Hedegård. Nano Lett., 10, 1657, 2010.
[3] Jing-Tao Lü, M. Brandbyge, P. Hedegård, T. N. Todorov, and D. Dundas. Phys. Rev. B,
85, 245444, 2012.
[4] Daniel Dundas, Eunan J. McEniry, and Tchavdar N. Todorov. Current-driven atomic
waterwheels. Nature Nanotech., 4(2):99–102, FEB 2009.
[5] Jing Tao Lü, P. Hedegård, and M. Brandbyge. Phys. Rev. Lett., 107, 046801, 2011.
[6] S. Ulstrup, T. Frederiksen, M. Brandbyge, Phys. Rev. B., 86, 245417, 2012.
-6!36/,&#/3!47- !3733!-6
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For several years we have worked on a class of interatomic forces that arise as a result of
departures from in non-equilibrium in systems of electrons and nuclei. This talk will give a
brief outline of these forces along with simple examples to illustrate some of the physics that
they reflect. An attempt will be made to seek to clarify the connection between these forces
and forces in classical flow problems.
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Department of Chemistry & Biochemistry University of California, San Diego
La Jolla, CA 92093-0340
The progress of the experimental capabilities in the field of molecular electronics brings
many new theoretical challenges. One of them is electron and energy transport at
resonance, which is probably the most important regime for possible future applications such
as logic and memory molecular devices. Standard quantum field theory methods mostly
utilized today by molecular electronics community become inconvenient when
oxidation/reduction of a molecule leads to a significant change in its electronic and vibrational
structure, or when the Born-Oppenheimer approximation fails. In such situations, a
description of electron and energy transport utilizing a basis of many-body molecular states
(rather than single-particle molecular orbitals) is desirable. The latter is also a way to
introduce quantum chemistry methods into molecular transport simulations.
Here we present our efforts to develop techniques combining generality of quantum field
theory methods with description of transport in the language of many-body molecular states.
Within numerical examples we compare our results to those of standard approaches, which
include scattering theory, quantum master equation, and nonequilibrium Green function
technique.
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Department of Advanced Materials Science, University of Tokyo, Kashiwa, Japan, RIKEN,
Wako, Japan
Ultimate spatial resolution of scanning tunneling microscope (STM) enables us to observe
the inner electronic, vibrational [1-7] and spin [8-11] structures of a molecule adsorbed on
solid surfaces. Environment of a molecule such as symmetry of the adsorption site and
spatial distribution of electronic structure can be defined experimentally, followed by a
precise consideration based on theory.
Spin nature of a molecule is strongly modified by the interaction with the substrate. An
iron(II) phthalocyanine (FePc) molecule when adsorbed on Cu(110), spin state of Fe atom
converts from triplet to singlet due to the strong coupling of Fe d states with the Cu. Whereas
on oxidized Cu(110), triplet state is maintained while the symmetry of the ligand field
surrounding the Fe atom is lowered, resulting in switching the magnetic anisotropy from the
easy plane of the bulk to the easy axis.[8] Recent DFT calculation studies have successfully
unveiled the physics behind.[9,10]
The Kondo effect is caused when FePc is adsorbed on Au(111). With the combined study of
density functional theory and a numerical renormalization group calculation with experimental
study using scanning tunneling microscopy, we found a novel Kondo effect. This is caused
by tuning the symmetry of the ligand field of molecule through the local coordination to the
substrate. For FePc in the on top configuration where fourfold symmetry around the Fe2+ ion
is held, the orbital degrees of freedom survive, resulting in the spin + orbital SU(4) Kondo
effect. In contrast, the reduced symmetry in the bridge configuration freezes the orbital
degrees of freedom, leading to the spin SU(2) Kondo effect. These results provide a novel
example to manipulate the many-body phenomena by tuning the local symmetry.[11-13]
The successive spectral evolution of the Kondo resonance state was investigated from a
single FePc molecule to the two-dimensional lattice on Au(111) by interrogating the individual
molecules with a scanning tunneling microscope. A sharp Kondo peak appears in the singleimpurity regime, which broadens and splits as the lattice builds up. The origin of spectral
evolution together with the electronic ground state of the lattice are discussed based on the
competition of the Kondo effect and Rudermann–Kittel–Kasuya-Yosida coupling between the
molecular spins.[11]
References :
[1] Y. Kim, T. Komeda, and M. Kawai, Phys. Rev. Lett. 89 (2002) 126104.
[2] S. Katano, M. Trenary, Y. Kim and M. Kawai, Science 316 (2007) 1883.
[3] T. Komeda, Y. Kim, M. Kawai, et al., Science 295 (2002) 2055.
[4] Y. Sainoo, Y. Kim, T. Okawa, et al., Phys. Rev. Lett. 95 (2005) 246102.
[5] M. Ohara, Y. Kim and M. Kawai, Phys. Rev. Lett. 100 (2008) 136104.
[6] K. Motobayashi, Y. Kim, H. Ueba and M. Kawai, Phys. Rev. Lett. 105 (2010) 076101.
[7] H.-J. Shin, J. Jung, K. Motobayashi, et al., Nature Materials 9 (2010) 442-447.
[8] N. Tsukahara, N. Takagi, Y. Takata, et al., Phys. Rev. Lett. 102 (2009) 167203.
[9] Jean-Pierre Gauyacq, Frederico D. Novaes, and Nicolás Lorente, Phys. Rev. B 81
(2010) 165423.
[10] Jun Hu and Ruqian Wu, Phys. Rev. Lett. 110 (2013) 097202.
[11] N. Tsukahara, S. Shiraki, S. Itou, N. Ohta, N. Takagi, and M. Kawai, Phys. Rev. Lett. 106
(2011) 187201.
[12] E. Minamitani, N. Takagi, et al., e-J. Surf. Sci. Nanotech. 10 (2012) 38.
[13] E. Minamitani, N. Tsukahara, N. Takagi, et al., Phys. Rev. Lett. 109 (2012) 086602.
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IEAP, Christian-Albrechts-Universität zu Kiel
Elevated currents in the scanning tunneling microscope may be used to induce various
manipulation and switching effects at surfaces. In this talk we will discuss experiments which
aim at controlling the spin state of adsorbed molecules through the injection of current or by
manipulating ligands at metallic centers. Moreover, we will analyse inelastic processes that
lead to the emission of photons.
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EHE7<2 CEE3/ CE36/&; CEE/9!4 - E/3!-6! 1. Institut des Sciences Moléculaires d’Orsay, CNRS-Université Paris-Sud, Orsay, France
2. Departament de Engenyeria Electronica, Escola Tecnica Superior d’Engenyeria,
Universitat Autònoma de Barcelona, Bellaterra, Spain
3. Centre d’investigaciò en Nanociència i Nanotecnologia (CSIC-ICN), Bellaterra, Spain
The development of low-T high resolution Scanning Tunnelling Microscopy (STM) and
Spectroscopy (STS) allowed to study in detail magnetic excitations at the atomic scale, an
important step in electronics miniaturisation. It appears that an electron tunnelling between
an STM tip and a surface through an adsorbate can very efficiently induce magnetic
transitions in the adsorbate, i.e. change its magnetic moment (see e.g. a review in [1]). We
developed a theoretical quantal treatment of these magnetic excitations processes, termed
strong coupling approach; it applies to local spin excitation [1]. Two applications will be
presented: an example of single adsorbates on a surface and an example of chains of
adsorbed atoms.
Excitation of individual Fe-Phthalocyanine molecules adsorbed on CuO/Cu(110) surfaces by
tunnelling electrons was studied experimentally by Tsukahara et al [2]. Magnetic excitations
were revealed by the existence of steps in the adsorbate conductance as a function of the
junction bias. The strong coupling approach allows quantitatively accounting for the
experimental observations and in particular for the very large inelastic fraction in the
tunnelling current [3].
A recent experimental study by Loth et al [4] revealed that chains of Fe atoms on a
CuN/Cu(100) surface couple anti-ferromagnetically (AFM) to form two Néel states with
alternating spin directions on the atoms along the chain. Furthermore, they could show that
electrons tunnelling from an STM tip through one of the Fe atoms provide an efficient switch
between the two quasi-stable Néel states, an appealing achievement in the context of
developing atomic scale information storage. The transitions between the various magnetic
states of the chain induced by tunnelling electrons had been studied using the strong
coupling approach. Our results, in good agreement with the experimental findings, identify
three different switching processes dominating in different ranges of STM bias, V: -at low V,
direct transitions between Néel states induced by a single electron-chain interaction -in the
intermediate V range (6-10 mV), an indirect process: the electron excites the chain into an
intermediate state (quantized spin wave modes) that later decays to the Néel states -at high
V (above ~10mV), an indirect process involving domain wall formation as intermediate
states.
The above three mechanisms for Néel states switch are quite different from the more usual
local spin-flip mechanism at play e.g. in magnon excitation in ferromagnetic chains.
Switching between the two Néel states in a chain requires the flip of all the local spins in the
chain and the quantal correlations in the chain (mixing between different configurations of
local spins) yield the driving force of the three above mechanisms for Néel switching.
1. J.P.Gauyacq, N.Lorente and F.D.Novaes, Prog.Surf.Sci. 87 (2012) 63
2. N.Tsukahara, K.Noto, M.Ohara, S.Shiraki, N.Takagi, Y.Takata, J.Miyawaki, M.Taguchi,
A.Chainani, S.Shin and M.Kawai, Phys. Rev. Lett. 102(2009) 167203
3. J.P.Gauyacq, F.D.Novaes and N.Lorente, Phys.Rev. B 81 (2010) 165423
4. S.Loth, S.Baumann, C.P.Lutz, D.M.Eigler and A.J.Heinrich, Science 335 (2012) 196
5. J.P.Gauyacq, S.M.Yaro, X.Cartoixà and N.Lorente, Phys.Rev.Lett. 110 (2013) 087201
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Nanoscale Physics Research Laboratory
School of Physics and Astronomy
University of Birmingham
Birmingham B15 2TT, U.K.
Atomic manipulation is the extreme limit of nanotechnology. I will discuss the manipulation
(specifically, desorption, dissociation and re-configuration) of polyatomic molecules –
chlorobenzene (C6H5Cl or PhCl) and polychlorinated biphenyls (PCBs) – anchored to a
silicon surface, with a focus on new mechanisms [1] for atomic manipulation via electron
injection. Such mechanisms may (eventually) be relevant to chip-scale molecular
manufacturing.
(i) Site-specific non-local atomic manipulation (leading to molecular desorption) of PhCl [2]:
effectively this is 'remote control' of molecular manipulation, and occurs via (a) the injection
of charge far away from the molecule at a specific surface atomic site followed by (b) charge
transport across the Si(111)-7x7 surface to the target molecule. This non-local mechanism
also calls into question a body of published cross-sections and thus may also have
implications for solar energy harvesting.
(ii) Thermally activated C-Cl bond dissociation in PhCl (one electron mechanism) [3]: we find
an Arrhenius energy barrier to one-electron dissociation of 0.8 ± 0.2 eV, which we correlate
experimentally with the barrier between the chemisorbed and physisorbed (precursor) states
of the molecule. Thermal excitation promotes the target molecule from a state where oneelectron dissociation is suppressed to a transient state where efficient one-electron
dissociation, analogous to the gas phase negative ion resonance process, occurs. The
mechanism may apply in many surface systems and not just in STM manipulation but also in
photon and electron beam stimulated processes.
(iii) Intramolecular site- and energy-selective manipulation of PCB molecules [4]: the two
benzene rings of the molecule bond in different fashions to the surface. Several competing
manipulation outcomes are identified, notably molecular desorption via electron injection into
the strongly bonded ring and re-configuration of the molecule via injection into the weakly
bonded ring, each with different energy thresholds which align with STS measurements.
1.
2.
P.A. Sloan and R.E. Palmer, Nature 434 367 (2005).
P.A. Sloan, S. Sakulsermsuk and R.E. Palmer, Phys. Rev. Lett. 105 048301 (2010); see
also “Electron 'submarines' help push atoms around”, E.S. Reich, New Scientist, 31 July
2010, p. 11.
3. S. Sakulsermsuk, P.A. Sloan and R.E. Palmer, ACS Nano 4 7344 (2010); see also
"Physisorbed molecules take the heat", In Nano, ACS Nano 4 7040 (2010).
4. T.
Pan, S. Sakulsermsuk, P.A. Sloan and R.E. Palmer, J. Am. Chem. Soc.
(Communications) 133 11834-11836 (2011).
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Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich and JARA – Fundamentals of
Future Information Technology
Rapid instrumental and methodological developments that occur in the field of scanning
probe microscopy (SPM) constantly extend our abilities to probe and manipulate individual
nanoscale adsorbates. One of the exciting and challenging areas within the SPM field is the
investigation of large organic molecules. A large size, anisotropic shape and numerous
chemical functionalities characteristic for organic molecules introduce considerable
difficulties to their studies. The arising complexity is very challenging both for the experiment
and the theory. However, the same complexity also becomes a source of new physical
phenomena showing interesting potentials for future technological applications.
In my contribution I will report on our latest experimental studies of organic molecules
adsorbed on atomically clean metal surfaces. Following the canons of surface science we
concentrate on detailed investigations of the very well characterized prototypical molecular
systems with a purpose of fundamental understanding of their properties. I will focus on the
two different facets of our research. The first one is related to our attempts of improving the
imaging of large organic molecules with a low-temperature scanning tunneling microscope
(LT-STM) by decorating the STM tip with the atomic and molecular adsorbates (H2, D2, Xe,
CO, CH4). It will be shown that the particle decorating the STM tip acts as a nanoscale force
sensor that is able of transducing the short-range force into the variations of the tunneling
conductance. In the second part I will describe our experimental effort focused on realization
of a reliable single-molecule wire. Employing the combination of LT-STM wit non-contact
atomic force microscopy (NC-AFM) we contact and lift large π-conjugated molecules from
the surface of a metal bringing them into a vertical-standing geometry in which they are
bridging the junction between the two metal leads thus acting as molecular wires. It will be
demonstrated how the simultaneous AFM/STM measurements help us reaching an
unprecedented degree of control over the structure and the charge transport properties of the
single-molecule wire junction.
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1
Faculty of Physics, Center for Nanointegration Duisburg-Essen (CeNIDE), University of
Duisburg-Essen, Lotharst. 1, D-47057 Duisburg, Germany
2
Centre d'Investigació en Nanociència i Nanotecnologia (CSIC-ICN), Campus UAB, E-08193
Bellaterra, Spain
3
Institut des Sciences Moléculaires d'Orsay, CNRS-Université Paris-Sud 11, UMR 8214,
Bâtiment. 351, Université Paris-Sud, F-91405 ORSAY Cedex, France
Noise is generally considered as a nuisance. However, it may contain valuable information
about atomic or molecular motion. Here, we show how signals can be extracted by a full realtime characterisation of the random telegraph noise in the current of a scanning tunneling
microscope. The hopping rate, the noise amplitude and the relative occupation of the
involved states are measured as a function of the tunneling parameters providing spatially
resolved maps. In contrast to standard STM, our data give access to transiently populated
states revealing an electron-driven hindered rotation between the equilibrium and two
metastable positions of an individually adsorbed molecule. The results for individually
adsorbed copper phthalocyanine molecules on Cu(111) are corroborated by density
functional theory calculations.
-!+46&41!63/4/1<:&6%47H6/,&3!4/+76&/-
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Lehrstuhl für physikalische Chemie I, Ruhr-Universität Bochum, Bochum, Germany
[email protected]
Scanning tunneling microscopy, inelastic tunneling spectroscopy, and d²I/dV²-mapping at low
temperatures are used to locally detect vibrations of molecules, surface phonon excitations,
and inelastic Friedel oscillations for the system meta-dichlorobenzene adsorbed on
herringbone reconstructed Au(111). The spatial variation of different vibrational modes as
measured in IETS spectra differs for adsorption in different domains of the reconstruction.
The spectra are compared to DFT calculated selection rules of the modes. Also phonon
spectra differ on different domains [1]. Mapping of the surface phonons in d²I/dV²-maps lead
to atomic resolution. We relate this to the excitation probability of the phonons. Finally,
surface electrons that are scattered at the molecules lead to specific standing wave patterns
in the d²I/dV²-maps that we explain to be inelastic Friedel-like oscillations based on
comparison to Green’s function calculations [2]. These studies demonstrate the high
sensitivity of low-temperature STM to the spatial variation of inelastic phenomena.
[1] H. Gawronski, M. Mehlhorn, K. Morgenstern, Science 319 (2008) 930
[2] H. Gawronski, J. Fransson, K. Morgenstern, Nano Letters 11 (2011) 2720–2724.
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Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 Donostia-San
Sebastián (Spain)
Sykes et al. [1] have reported that H buried beneath Pd(111) diffuses through the metal upon
injection of electrons from a scanning tunneling microscope (STM) tip. The presence of
subsurface H species, that are imaged by STM as bright features on the surface, evidences
that the diffusion phenomenon is taking place well below the surface. Crucially, the
experimental H extraction rates are similar for both positive and negative bias voltages. This
is a counterintuitive observation, as tip electric field effects are screened out at the deep
metal layers and, moreover, there is a large asymmetry between electrons and holes in the
Pd density of states. We have constructed a diffusion model for interstitials based in a
truncated harmonic potential and quantum tunneling. Density Functional Theory provides
potential energy surfaces and electron-phonon coupling data that can be used to
parameterize the model and obtain quantitative excitation rates. In the case of H and D in Pd,
we show that d-band electrons do not take part in the diffusion mechanism. The interstitial
vibrational excitation is driven by the s-band electrons only, which explains the observed
symmetry [2].
[1] E.C.H. Sykes, L.C. Fernandez-Torres, et al., Proc. Natl. Acad. Sci. U.S.A. 102 (2005)
17907
[2] M. Blanco-Rey, M. Alducin, J.I. Juaristi, P.L. de Andres, Phys. Rev. Lett. 108 (2012)
115902
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Institut für Experimentalphysik, Freie Universität Berlin, Berlin 14195
Spain CIC nanoGune, Tolosa Hiribidea 78, San Sebastian – Donostia 20018, Spain
Ikerbasque, Basque foundation for Science, Bilbao 48011, Spain.
STM is an ideal probe to investigate not only electronic structure, but also excitations of
individual adsorbates on surfaces. Combination of energy, space and time resolution is a
powerful approach to track elementary processes involved in fields like chemistry, molecular
electronics, magnetism, Bringing the tip of a STM to the proximity of a molecule allows us
to also investigate charge transport through molecular junctions in a controlled configuration
and inspect different elementary excitations induced by electrons. In this talk, I will present
recent results on inelastic phenomenology induced by tunneling current, like spin excitations,
molecular conformational transformations, or vibrational heating. An interesting approach is
the combination of electron transport measurements with two additional experimental
techniques: Force spectroscopy Light spectroscopy.
-Spin excitations have been observed in paramagnetic molecules on a superconducting
substrate. An interesting outcome is that the lifetime of excited states amounts to a few
nanoseconds, much larger than on normal metal surfaces. This is interpreted as due to the
depletion of electronic states within the superconducting energy gap at the Fermi level, which
prohibits pathways of energy relaxation into the substrate.
- Molecular conformational changes are followed during the formation of molecular bridges
between the tip of the STM and the surface. Here, we measure forces revealing the
intramolecular flexibility and deformations occurring during the formation of the molecular
junction. We resolve the strong effect that specific conformations cause in the transmission
through the junction.
- Tunneling electrons through molecular junctions also induce light emission mediated by
localized plasmon modes at the tunnel junction. The spectroscopic characterization of
emitted photons reveals “anti-stokes”-like phenomena, which we interpret as induced by hot
molecular modes, excited by inelastic tunneling. This allows us to provide an insight into
vibrational temperature induced by inelastic electrons.
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1
Donostia Donostia International Physics Center (DIPC)
IKERBASQUE , Basque Foundation For Science
3
Dpt. of Mechanical Engineering, University of Michigan, USA
4
Dpt. of Chemistry, University of Konstanz (Germany)
5
Department of Chemistry, University of Konstanz (Germany)
6
Departmen of Physics, University of Konstanz (Germany).
* email: [email protected]
2
The azobenzene class of molecules has become an archetype of molecular photoswitch
research, due to their simple structure and the significant difference of the electronic system
between their cis and trans isomers. However, a detailed understanding of the charge
transport for the two isomers, when embedded in a junction with electrodes is still lacking.
With the aim of clarifying this issue, we investigate charge transport properties through single
Azobenzene-ThioMethyl (AzoTM) molecules in a mechanically controlled break junction
(MCBJ) system at 4.2 K. Single-molecule conductance, I-V characteristics, and IETS spectra
of molecular junctions are measured and compared with first-principles transport
calculations.
Our measured conductance traces clearly show that cis isomers have a larger conductance
than trans isomers. Our transport calculations show that the difference in conductance of the
isomers is due to the difference of their corresponding resonant states, in agreement with
experimental findings.
Experimental IETS spectra of Au-AzoTM-Au junctions exhibit distinct features for cis and
trans isomers. The origin of such features has been elucidated based on a thorough analysis
of simulated IETS spectra, which allows us to conclude that the observed differences in
experimental IETS are indeed caused by the cis-trans conformation.
In conclusion, our studies elucidate the origin of a slightly higher conductance of junctions
with cis isomer and demonstrate that IETS spectra of cis and trans forms show distinct
vibrational fingerprints that can be used for identifying the isomer.
Figure
1: (a) Experimental
and
(b)
theoretical
IETS
spectra for cis and
trans
isomers
(averaged over
several
configurations).
[1] Y. Kim, A. Garcia-Lekue, D. Sysoiev, T. Frederiksen, U. Groth, E. Scheer. Phys. Rev. Lett.
109, 226801 (2012)
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A. M. Prokhorov General Physics Institute, RAS, Vavilova 38, Moscow, Russia.
2
Division of Nanotechnology and New Functional Material Science, Graduate School of
Science and Engineering, University of Toyama, Toyama, 930-8555 Japan.
3
School of Computer Science, Physics and Mathematics, Linnaeus University, 391 82
Kalmar, Sweden.
We analyse the peculiarities and mechanisms of rotational motion of a single acetylene
molecule on a Cu(001) surface by STM observed in the pioneering work of Stipe, Rezaei,
and Wo [1]. Rotation with a higher threshold voltage ~360 meV occurs if enough energy
stored in the high- frequency CH stretch mode excited by tunneling electron is transferred to
the rotational mode (reaction coordinate). The anharmonic coupling of the CH mode with the
hindered rotation mode is found to be responsible for a crossover from a single to multiple
electron process for tunneling currents higher than 10 nA. The lower threshold voltage for
rotation at ~240 meV is attributed to a combinational process of inelastic scattering of
tunneling electrons on a pair of lower-energy vibrational excitations of the acetylene
molecule. The involved theoretical approaches include ab-initio DFT modeling of the
adsorbed acetylene on Cu(001) and its vibrational modes, nonequilibrium Keldysh-Green’s
functions technique to describe the inelastic electron scattering, and Pauli master equation
for rotational mode ladder climbing. This allows us to reproduce nicely the original
experimental results (see in the Figure), and to identify the vibrational modes responsible for
rotation and their anharmonic coupling.
Figure: Rotation yield per electron as a
function of bias voltage at fixed tunneling
current I = 40~nA. Circles are the
experimental data from [1]. Blue dashed and
red dash-dotted lines are the one-electron
and two-electron processes via initial
excitation of the high frequency CH stretch
mode, and green dotted line is the
combinational process. Black solid line
corresponds to a sum of all processes.
1. B. C. Stipe, M. A. Rezaei, and W. Ho, Phys. Rev. Lett. 81, 1263 (1998).
- !346- &-$
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Shiri Burema and Marie-Laure Bocquet
Laboratoire de Chimie, Ecole Normale Supérieure de Lyon, 46 Allée d’Italie, 69364
CEDEX07 Lyon, France
Density Functional Theory (DFT) has now reached the point to mimic quantitatively one
spectroscopic mode of the Scanning Tunneling Microscope (STM) comprising of the inelastic
detection way, called Inelastic Electron Tunneling Spectroscopy (IETS). In this talk, we
present a selection of hybrid interfaces ranging from functionalized benzene derivatives
(«small» aromatic systems) to ligated metalloporphyrins («big» aromatic systems) deposited
onto ideal transition metal surfaces, for which we compute the IETS spectra from First
Principles. Our ab initio screening of « small » interfaces’s inelastic responses permits to
disentangle subtle adsorbate features like denticity, orientation and isomery [1] and to point
out two costless criteria that turn on the IETS signal : an extension into vacuum of the
symmetry- allowed tunneling state [2] and an excess of electron density in the area
contacting the substrate [3]. In contrast, the « big » system - the adsorbed cobalttetraphenylporphyrin Co-TPP) - is driven by experiment : the IETS measurements performed
in TUM Munich (W. Auwärter and J. Barth) evidence a unique signal at a sample bias voltage
of about 31 mV for the NO- ligated Co porphyrin on Ag(111), while no inelastic signal can be
detected on the bare porphyrin. By means of extremely large ab initio IETS simulations, we
reproduce at best the experimental measurements for both ligated and non-ligated Co-TPP
molecules, permitting to identify the unique active vibration of the NO-ligated Co-TPP to be a
Co-N-O in-plane rocking mode [4]. IETS activity can thus be used as an indicator to sense
and probe central, axial NO ligation on adsorbed metallo-porphyrins. Our findings further
emphasize the discriminative power of IETS in order to become a well- understood and
standard characterization tool in surface science.
[1] M.-L. Bocquet, H. Lesnard, N. Lorente Phys. Rev. Lett. 2006 96, 096101 ; S.R. Burema,
M.L. Bocquet, Nanotechnology 2012, 23, 315702
[2] S.R. Burema, N. Lorente, M.L. Bocquet. J. Chem. Phys. 2012 136, 244507
[3] S.R. Burema, M.L. Bocquet, J. Phys. Chem. Lett. 2012 3, 3007
[4] S.R. Burema, K. Seufert,W. Auwärter, J. V. Barth, M.L. Bocquet, 2013 submitted
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1Department of Physics and Astronomy & Petersen Institute of NanoScience and
Engineering, University of Pittsburgh, Pittsburgh PA 15260 USA
2Hefei National Laboratory for Physical Sciences at Microscale & Department of Physics,
University of Science and Technology of China (USTC), Hefei 230026, China
3Department of Electrochemistry and Conducting Polymers, Leibniz-Institute for Solid State
and Materials Research (IFW), Dresden, Germany
4Hefei National Laboratory for Physical Sciences at Microscale & Department of Materials
Science and Engineering, University of Science and Technology of China (USTC), Hefei
230026, China
We demonstrate a single-molecule switch based on tunneling electron-driven rotation of a
triangular Sc3N cluster within an icosahedral C80 fullerene cage among three pairs of
enantiomorphic configurations.1,2 Scanning tunneling microscopy imaging of switching
within single molecules and electronic structure theory identify the conformational isomers
and their isomerization pathways. Bias- dependent action spectra and modeling identify the
antisymmetric stretch vibration of Sc3N cluster as the gateway for energy transfer from the
tunneling electrons to the cluster in-plane and axis-switching rotation. At sufficiently high bias
voltages to tunnel through the frontier orbitals of Sc3N@C80 molecule, electronically
nonadiabatic processes involving multistep conformational changes are activated. The
hierarchical switching of conductivity through the internal cluster motion among multiple
stationary states while maintaining a constant shape, is advantageous for the integration of
endohedral fullerene-based single-molecule memory and logic devices into parallel
molecular computing architectures.
[1] Huang, T., et al. "Molecular Switch Based on Current-Driven Rotation of an Encapsulated
Cluster
within
a
Fullerene
Cage."
Nano
Lett.
11,
5327
(2011).
[2] Huang, T., et al. "Molecular Switch Based on Current-Driven Rotation of an Encapsulated
Clu A multi-state single-molecule switch actuated by rotation of an encapsulated cluster
within a fullerene cage." Frontiers Article in. Chem. Phys. Lett. 552, 1 (2012).
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E!
Division of Nano and New Functional Materials Science,
Graduate School of Science and Engineering, University of Toyama
Toyama, Japan
(Retired on 31, March 2013)
Adsorbate reactions on surfaces constitute the most fundamental step in many surface
chemical reactions. New avenue of nano science and technology has opened for a single
atom switch realized by a controlled shuttling of a Xe atom between a tip of a scanning
tunneling microscope (STM) and a metal surface [1], and single molecule vibrational
spectroscopy (inelastic electron tunneling spectroscopy, IETS) as well as viewing single
molecule reactions induced by vibrational excitation [2] with an STM. One of the recent
highlights include four wheel wheeled molecule on a metal surface [3]. Single molecule
motions induced by heat transfer from ultrafast laser generated hot electrons to the relevant
vibrational degrees of freedom has also been observed in real apace [4,5].
I will talk about how much I have enjoyed working with my colleagues on single molecule
reactions in real space/time in terms of vibrational mode coupling [6, 7]. Let me first to revisit
back to my unforgettable work with Bo Persson and M. Kawai group on a CO hopping on
Pd(110) [8]. I plan to give something behind an idea of anharmonic coupling which has not
been described before. Many works on IETS with S. Thihodeev [9] and M. Paulsson [10]
enabled me to formulate a theory of action spectroscopy for single molecule reactions [11,12]
(originally proposed by Kawai group [13,14]). The unified and general theory has been
completed with T. Frederiksen [15] for the analysis of real space observation of hydrogen
atom relay reaction in water-hydoroxyl chain on Cu(110)[16]. Using this formula I was able to
extract anharmonic coupling strength between the C-O stretch mode and the frustrated
translation mode from a nice reproduction of the experimental result [17].
The idea of vibrational mode coupling has been extended to study a real time monitoring of
molecular motions on metal surfaces. Bo Persson again joined me to formulate an indirect
heating of a reaction coordinate mode [8]. This has been successfully applied to explain the
experimental results of CO hopping on a stepped Pt surface [18,7] and on a Cu(111)
[5,19,20] by heat transfer from hot electrons in metals. In both cases it has been shown that
excitation of the frustrated rotation forms a precursor state for lateral hopping as first
beautifully demonstrated by Bonn et al [6]. I believe that intermode coupling clarifies the
elementary process behind an empirical hot-electron temperature dependent friction model
introduced in a conventional heat transfer equation. Recently I have tried to estimate a
hopping ratio (along/across row) and desorption rate of a single CO molecule on Cu(110) [4]
(see illustration by Bartels) using an advantage of the extensive density functional theory
calculations for the vibrational properties (vibrational energy, electron-hole pair damping and
intermode coupling) by N. Lorente[ 21].
I thank my colleagues for successful collaborations with me for many years, otherwise none
of my works had been completed. In addition to those named above, many thanks go to Y.
Kim, T. Komeda, T. Kumagai, K. Motobayashi, H. Okuyama, M. Brandbyge, K-H. Ernst, M.
Galperin, J. Güdde, U. Höfer, K. Morgenstern, R. Palmer, J.I. Pascual, H. Petek, M. Persson,
and M. Wolf who have shared very stimulating times with me. Finally, not at least, I would
like to express my deepest thanks to N. Lorente, M. Paulsson and T. Frederiksen for
organizing this workshop.
[1] D.M. Eigler, C.P. Luts, and W.E. Rudge, Nature 352, 600 (1991).
[2] B.C. Stipe, M. A. Rezaei, and W. Ho, Science 279, 1907 (1998), 280, 1732 (1998).
[3] T. Kudernac et al. Nature 479, 208 (2011).
[4] L. Bartels et al., Science 305, 649 (2004).
[5] M. Mehlhorn, H. Gawronski, and K. Morgenstern, Phys. Rev. Lett. 104, 076101 (2010).
[6] H. Ueba, Surf. Sci. 601, 5212 (2007).
[7] H. Ueba and B.N.J. Persson, Phys. Rev. B 77, 035413 (2008).
[8] T. Komeda, Y. Kim, M. Kawai, B. N. J. Persson, and H. Ueba, Science 295, 2055 (2002).
[9] H. Ueba, S. G. Tikhodeev, B. N. J. Persson, in Current-Driven Phenomena in
Nanoelectronics, edited by T. Seideman
(Pan Stanford Publishing Ltd., Singapore, 2011).
[10] M. Paulsson et al., Phys. Rev. Lett. 100, 226604 (2008).
[11] H. Ueba and B. N. J. Persson, Phys, Rev. B 75, 041403(R) (2007).
[12] S.G. Thikodeev and H. Ueba, Phys. Rev. Lett. 102, 246101 (2009).
[13] Y. Sainoo et al., Phys. Rev. Lett. 95, 246102 (2005).
[14] K. Motobayashi, Y. Kim , H. Ueba, and M. Kawai, Phys. Rev. Lett. 105, 076101 (2010).
[15] T. Frederiksen, M. Paulsson, Y. Ootsuka, and H. Ueba, submitted.
[16] T. Kumagai et al., Nature Mat. 11, 167 (2012).
[17] H. Ueba, Phys. Rev. B. 86, 035440 (2012).
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18:10
17:30
16:50
15:40
15:00
13-15
12:10
11:30
10:20
9:40
9:00
Lunch
M. Blanco-Rey
Coffee
Various Manipulations
Chair: M. Alducin
Inelastic spectroscopy with sub-atomic resolution
K. Morgenstern
Revealing molecular dynamics through scanning
noise microscopy and spectroscopy
R. Möller
Dynamics at Surfaces V
Chair: M. Alducin
Poster session
Molecular junctions: A nonequilibrium atomic limit
M. Galperin
T. Todorov
Interatomic forces under current
B.N.J Persson
Tribology at the atomistic level
Workshop dinner
Starting at 21.00
Spin, Forces and Photons in Molecular Tunneling
Junctions
J.I. Pascual
Controlled switching molecule-electrode interfaces Electron-Phonon coupling and molecular dynamics Subsurface Hydrogen and Deuterium Manipulation
in the presence of current
by Ballistic Electrons
M. Brandbyge
Coffee
Electronic currents + dynamics
Chair: K. Morgenstern
Coffee
Dynamics at Surfaces I
Chair: M. Kawai
H. Okuyama
W. Hofer
Theory of scanning tunneling microsopy: studying
dynamic processes
M. Wolf
Probing the transient electronic structure in surface
femtochemistry
K. H. Ernst
Chirality in molecular recognition and dynamics at
surfaces
E. Chulkov
Relativistic effects in surface electronic structure of
solids: Bychkov-Rashba systems and topological
insulators
Lunch
Dynamics at Surfaces III
Chair: K. Morgenstern
Opening session
Chair: M. Kawai
R. Temirov
Imaging and control of large organic molecules
within a scanning probe microscopy junction
R. Robles
Site- and orbital-dependent charge and spin
manipulation in supported transition metal
phthalocyanines
R. Palmer
Atomic manipulation by electron injection
T. Komeda
Manipulation of Spin in Double Decker
Phthalocyanine Molecule
Coffee
Dynamics at Surfaces IV
Chair: M.-L. Bocquet
J.-P. Gauyacq
Excitation of magnetic adsorbates by tunnelling
electrons: atoms and chains
M. Persson
Charging and Bond formation of Adsorbates on
Ultrathin, Insulating Films Supported by a Metal
Substrate
Coffee
Spin Manipulation I
Chair: A. Garcia-Lekue
R. Berndt
Manipulation of the spin and charge states of
adsorbed molecules
A. Groß
Molecule-surface interactions at complex metal-gas
and metal-liquid interfaces studied by ab initio
molecular dynamics simulations
M. Kawai
Local Symmetry Rules Spin Ground State: FePc on
Au(111)
M. Alducin
Does N2 adsorption increase on strained Fe
monolayers?
Wednesday
Spin Manipulation II
Chair: M.-L. Bocquet
Tuesday
Dynamics at Surfaces II
Chair: A. Garcia-Lekue
Arrival / registration
Monday
Closing + Lunch
Vibrationally mediated single molecule reactions in
real space and in real time
H. Ueba
A multi-state single-molecule switch actuated by
rotation of an encapsulated cluster within a
fullerene cage
H. Petek
Understanding Inelastic Electron Spectroscopy of
single adsorbates on metal surfaces : start « small
», finish « big »
Coffee
Dynamics at Surfaces VI
Chair: M. Paulsson
M.-L. Bocquet
Mechanisms of rotation of a single acetylene
molecule on Cu(001) by tunneling electrons in STM
S. Tikhodeev
Azobenzene-Based Single-Molecule Junctions:
Charge Transport Mechanism and IETS
Fingerprints
A. García-Lekue
IETS
Chair: M. Paulsson
Thursday