En complément des journées annuelles qui permettront à notre communauté de se réunir, une des premières initiatives du GdR-NS-CPU consistera en l’organisation de visio-séminaires toutes les 3 à 4 semaines. L’idée est d’inviter, dans une première partie, un(e) jeune chercheur(se) travaillant dans une équipe du GdR (idéalement en thèse ou en post-doc) pour une présentation de 20’ +10’ et, dans une seconde partie, un(e) scientifique plus établi(e), la plupart du temps étranger, au cours d’un séminaire de 45’ + 15’ nous permettant de nous ouvrir à de nouveaux horizons. Nous essaierons d’alterner les thématiques autant que possible, tout en gardant comme « coeur de cible » des collègues réalisant des études de microscopie/spectroscopie en champ proche sous ultra-vide.

Zoom access to the seminar: Click here

Prochain Séminaire

Jeudi 04 juillet

10h30 – Nanoscale Charge Measurements with Charge Force Microscopy  – Philipp Rahe – University of Osnabrück (Germany)

Abstract:
Philipp Rahe

Institute of Physics, University of Osnabrück, 49076 Osnabrück, Germany
E-mail:

The foundations of modern technology are undoubtedly linked to the physical properties of the electron. Consequently, the behaviour of electrons within nanoscale structures is a key aspect within the fields of catalysis, energy storage, or quantum sensors. While it has early been shown that the sensitivity of dynamic scanning probe microscopy (SPM) measurements is sufficient to detect single electrons [1], the experimental quantification of the charge magnitude within nanoscale structures is still under critical discussion. In particular, state-of-the-art Kelvin Probe Force Microscopy (KPFM) measurements commonly do not yield calibrated results for charge magnitudes as, for example, not only the choice of the KPFM technique [2], but also several experimental parameters [3] have been identified to have an impact on the KPFM signal magnitude. These findings render a general interpretation of experimental KPFM data for charged systems and the extraction of meaningful physical parameters an extremely challenging task.

Here, we introduce charge force microscopy (CFM) as a quantitative method for nanoscale charge measurements [4], develop the corresponding theory [5], and present model calculations that give evidence for the relation between the CFM measurement data and the charge magnitude in question. A detailed discussion of the sensitivity to various parameters is included. Because charge measurements are generally prone to non-local effects, we carefully untangle the contribution of charges at different positions from the signal of interest that is caused by a central charge.

Experimentally, we investigate Au nanoparticles grown on CeO2(111) under ultra-high vacuum conditions. We discuss the challenges of determining the required parameters for CFM from the experiments by introducing a two-step data analysis procedure: First, the signal measured at twice the electrical modulation frequency, 2fel, is used to determine parameters for an electrostatic model. Second, this electrostatic model is used to fit the distance-dependent CFM data. For both steps, we use data acquired with different oscillation amplitudes to enable data validation by force curve alignment [6].

References
[1] Klein and Williams, Appl. Phys. Lett. 79, 1828 (2001)
[2] S. A. Burke et al., Nanotechnology 20, 264012 (2009)
[3] A. Liscio et al., Adv. Funct. Mater. 16, 1407 (2006)
[4] D. Heile, PR et al., Phys. Rev. B. 108, 085420 (2023)
[5] J. L. Neff and P. Rahe, Phys. Rev. B 91, 085424 (2015), H. Söngen, PR et al., J. Appl. Phys. 119, 025304 (2016)
[6] D. Heile, PR et al., Phys. Rev. B 103, 075409 (2021)


Séminaires passés

Pour accéder à la liste des séminaires de 2021, cliquez ici

Pour accéder à la liste des séminaires de 2022, cliquez ici

Pour accéder à la liste des séminaires de 2023, cliquez ici


2024

Mardi 04 juin

11h00 – Light induced phase transitions in quantum materials Matteo Calendra – University of Trento

Mardi 02 avril

15h30 – Quantum phases on the triangular adatom lattice Hanno H. Weitering – University of Tennessee

Mardi 15 janvier

11h – Molecular spin switches on surfacesManuel Gruber – Faculty of Physics, University of Duisburg-Essen, Duisburg, Germany


2023

Mardi 20 juin

10h30 – Electrically driven cascaded photon-emission in a single molecule – Katharina Kaiser
Katharina Kaiser
– IPCMS – Strasbourg (France)

11h – Electron quantum optics with graphene nanoribbons
Thomas Frederiksen
– Donostia International Physics Center (DIPC) – https://frederiksen.dipc.org/

Mardi 30 mai

10h30 – High Order Commensurate zwitterionic supramolecular network on HOPG
Gaelle Nassar
– CINaM (France)

11h – Atomic-Scale Optical Spectroscopy at Surfaces
Takashi Kumagai – Institute for Molecular Science (Okasaki, Japan)

Mardi 28 mars

10h – Lattices of Shiba states in supramolecular architectures
Gao Yingzheng
– ESPCI – QuantumSpecs (France)

11h – Searching for unconventional electronic states by high-resolution spectroscopic-imaging scanning tunneling microscopy
Tetsuo Hanaguri
– RIKEN Center for Emergent Matter Science (Japan)

Mardi 7 mars

11h – Mesoscale-ordered 2D polymers by on-surface photopolymerization
Markus Lackinger
– Technische Universität München & Deutsches Museum (Germany)

Mardi 24 Janvier

16h – 2D networks of C60 by STM
Maria Alfonso-Moro
– PhD defended in 12/2022 at Institut Néel under the supervision of Johann Coraux, Nicolas Rougemaille and Benjamin Canals

16h30 – Accessing non-equilibrium states at atomic scales
Jascha Repp
– Université de Regensburg, Allemagne


2022

Mardi 21 Juin

14h – Mapping magnetism with a molecular tip
Alex Fetida
– STM group, IPCMS, Strasbourg, France

14h30 – High-resolution SPM imaging of molecules with a functionalized probe
Pavel Jelinek
– Czech Academy of Sciences, Czech Republic

Mardi 24 Mai

10h30 – Metal Halide Perovskites: From Surface Properties to Material Stability and Device Stability
Jeremy Hieulle
– Department of Physics and Materials Science, University of Luxembourg, Luxembourg City L-1511, Luxembourg

11h – Atomically-resolved surface studies on In2O3(111): clean, hydroxylated, and with water
Ulrike Diebold
– Institute of Applied Physics, TU Wien, Vienna, Austria

Mardi 26 Avril

10h30 – Spin-Polarized Surface States of Pb Monolayers on Si(111)
Christian Brand
– Christophe Tegenkamp’s Lab – Leibniz Universität Hannover, Germany

11h – Single-molecule laser nanospectroscopy in STM for studying fundamental optical and energy conversion processes
Hiroshi Imada
– Yousoo Kim’s Lab – Riken, Wako, Japan

Mardi 22 mars

10h30 – Engineering topological superconductivity in a van der Waals heterostructure
Viliam Vano
– Liljeroth’s team – Aalto University, Finland

11h – Exploring the femtoscale
Franz J. Giessibl – Department of Physics, University of Regensburg, Germany

Mardi 22 février

10h30 – Free coherent evolution of a coupled atomic spin system initialized by electron scattering
Laëtitia Farinacci
– Otte Lab – Delft University, Netherlands – https://ottelab.tudelft.nl/person/laetitia-farinacci/

11h – Emergence of π-Paramagnetism in Engineered Graphene Nanostructures
Nacho Pascual
– CIC nanoGUNE, San Senbastian – Donostia, 20018, Spain

Mardi 18 Janvier

10h30 – Growth and study of 1D molecular chains decoupled from a metallic surface using thin insulating films for nano-optics
Remi Bretel
– Nanophysics@Surfaces group, Institut des Sciences Moléculaires d’Orsay, France

11h – On-surface synthesis of nanographene characterized by low-temperature atomic force microscopyimensional metal-organic nanosystems
Remy Pawlak
– Department of Physics, University of Basel Klingelbergstrasse 82, CH-4056 Basel, Switzerland


2021

Mardi 7 Décembre

CANCELED DUE TO COVID RESTRICTIONS

11h – Coordination chemistry at interfaces and the engineering of low-dimensional metal-organic nanosystems
Johannes V. Barth
– Physik Department E20, Technische Universität München, D-85748 Garching, Germany http://www.e20.ph.tum.de

On-site seminar: Department of Chemistry of ENS, Salle Ferdinand Berthier 29, rue d’Ulm, 75005 Paris

Mardi 16 Novembre

11h – Topological gaps and precursors of Majorana modes in artificial Shiba chains – Axe 1
Jens Wiebe
– Department of Physics, Universität Hamburg, Hamburg, Germany

Mardi 26 Octobre

10h30 – Thermally-induced magnetic order from glassiness in elemental neodymium Axe 3
 Benjamin Verlhac – SPM team – University of Nijmegen (Netherlands)

11h – Chemical stability of zigzag edges in carbon nanostructures Axe 1
Dimas G. de Oteyza – DIPC San Sebastian (Spain)

Mardi 5 octobre

11h – Molybdenum Disulfide on Au(111) – an outstanding playground for single molecule spectroscopy Axe 1
Christian Lotze – Freie Universität Berlin, group K. Franke

Mardi 14 Septembre

11h – Mechanisms of electron spin resonance driven by the electric field of an STM tip. Axe 5
Nicolas Lorente – Centro de Física de Materiales (CSIC) & Donostia International Physics Center
E-20018 San Sebastián, Spain

Mardi 20 Juillet

13h30 – The Water Forming Reaction on Palladium Nanoparticles Studied by Kelvin Probe Force Microscopy – Axe 4
Baptiste Chatelain – Aix-Marseille University, CNRS, CINaM, 13288 Marseille, France

14h – Are we there yet? The need for speed! – Axe 4
Peter Grutter – Department of Physics, McGill University, Montréal, Canada

Mardi 22 Juin

10h30 – Valley interference of a donor in 2H-MoTe2 – Axe 3
Valeria Sheina – C2N, Palaiseau, France

11h – Topological superconductivity in van der Waals heterostructures – Axe 3
Peter Liljeroth, Aalto University, Finland

Mardi 25 mai – 11h

Real space-time imaging of valence electron motion in molecules – Axe 2
Manish Garg
Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany

Mercredi 5 mai

10h – Présentation du GdR – David Martrou
10h30 – Séminaire court – Funneling energy at the molecular scale– Axe 2
Anna Roslawska, IPCMS Strasbourg
11h – Séminaire long – On-surface reactions and single-molecule charge transitions controlled by atom manipulation – Axe 1-4
Léo Gross, IBM Research – Zurich, 8803 Rüschlikon, Switzerland