A5068616892- Surface and Thin Film Phenomena
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Advanced Chemical Physics Studies
- Magnetic properties of thin films
- Graphene research and applications
- Surface Chemistry and Catalysis
- Molecular Junctions and Nanostructures
- Iron-based superconductors research
- 2D Materials and Applications
- Advanced Materials Characterization Techniques
- Chemical and Physical Properties of Materials
- Rare-earth and actinide compounds
- Organic and Molecular Conductors Research
- Electronic and Structural Properties of Oxides
- Supramolecular Self-Assembly in Materials
- Quantum many-body systems
- Characterization and Applications of Magnetic Nanoparticles
- Nanopore and Nanochannel Transport Studies
- Quantum Dots Synthesis And Properties
- Theoretical and Computational Physics
- Iron oxide chemistry and applications
- Silicon Carbide Semiconductor Technologies
- Nanomaterials for catalytic reactions
Laboratoire de Physique et d’Étude des Matériaux
2017-2024
ESPCI Paris
2015-2024
Université Paris Sciences et Lettres
2018-2024
Centre National de la Recherche Scientifique
2014-2024
Sorbonne Université
2014-2024
École Polytechnique Fédérale de Lausanne
2005-2019
Université Paris Cité
2018
Institut des NanoSciences de Paris
2012-2015
Université de Lorraine
2006-2010
Institut Jean Lamour
2009-2010
We demonstrate a giant Rashba-type spin splitting on semiconducting substrate by means of Bi-trimer adlayer Si(111) wafer. The in-plane inversion symmetry is broken inducing with Rashba energy about 140 meV, much larger than what has previously been reported for any semiconductor heterostructure. separation the electronic states their lifetime broadening, which directly observed angular resolved photoemission spectroscopy. experimental results are confirmed relativistic first-principles calculations.
The adsorption and ordering of the molecule terephthalic acid (TPA), 1,4-benzene-dicarboxylic C6H4(COOH)2, on reconstructed Au(111) surface has been studied in situ ultrahigh vacuum by scanning tunneling microscopy (STM) at room temperature. Two-dimensional (2D) self-assembled supramolecular domains evolve, wherein well-known one-dimensional (1D) carboxyl H-bond pairing scheme is identified. Since individual molecules occupy a distinct site usually extends over several substrate...
Abstract The achievement of both efficiency and stability in perovskite solar cells (PSCs) remains a challenging actively researched topic. In particular, among different environmental factors, ultraviolet (UV) photons play pivotal role contributing to device degradation. this work, by harvesting simultaneously the optical structural properties bottom–up‐synthesized colloidal carbon quantum dots (CQDs), cost‐effective means is provided circumvent UV‐induced degradation PSCs without...
We have studied the superconducting state of $2H\ensuremath{-}{\mathrm{NbSe}}_{2}$ by scanning tunneling spectroscopy along two different crystal orientations, $c$ and $a/b$ axes. Along axis a large gap is dominant in spectra, while smaller measured axis. show that these spectra are accurately described McMillan model where small induced through coupling to band associated with gap. In order assign gaps specific parts Fermi surface, electronic structure was using first-principles...
The Bi/Si(111) $(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})R30\ifmmode^\circ\else\textdegree\fi{}$ trimer phase offers a prime example of giant spin-orbit splitting the electronic states at interface with semiconducting substrate. We have performed detailed angle-resolved photoemission spectroscopy (ARPES) study to clarify complex topology hybrid bands. analysis ARPES data, guided by model tight-binding calculation, reveals previously unexplored mechanism origin splitting, which...
Using density functional theory, we investigate the electronic structure of alpha phase an antimony monolayer in its isolated form and contact to (111) surface gold. We demonstrate that single-layer actually displays a slightly modulated puckering stabilizes monolayer, not uniform one as often assumed. Moreover, it has dramatic consequences on band structure: material is semiconductor with low-dispersing bands near Brillouin zone center. By further application about 12% strain armchair...
We report scanning tunneling microscopy observations on the formation of 2D Co-based coordination compounds reconstructed Au(111) surface. Preorganized arrays Co bilayer islands are shown to be local reaction sites, which consumed in Co-terephthalate aggregates and regular nanoporous grids. The latter exhibit a planar geometry stabilized by smooth substrate. nanogrids based rectangular motif, is understood as an intrinsic feature cobaltous terephthalate sheet dominates over templating...
The adsorption of terephthalic acid [C6H4(COOH)2, TPA] on a Pd(111) surface has been investigated by means scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy, and near-edge absorption fine structure spectroscopy under ultrahigh vacuum conditions at room temperature. We find the coexistence one- (1D) two-dimensional (2D) molecular ordering. Our analysis indicates that 1D phase consists intact TPA chains stabilized dimerization self-complementary carboxyl groups, whereas in...
We have studied the interplay of a giant spin-orbit splitting and quantum confinement in artificial Bi-Ag-Si trilayer structures. Angle-resolved photoelectron spectroscopy reveals formation complex spin-dependent gap structure, which can be tuned by varying thickness Ag buffer layer. This provides means to tailor electronic structure at Fermi energy, with potential applications for silicon-compatible spintronic devices.
The spectroscopy of quasi-one-dimensional (1D) systems has been a subject strong interest since the first experimental observations unusual line shapes in early 1990s. Angle-resolved photoemission (ARPES) measurements performed with increasing accuracy have greatly broadened our knowledge properties bulk 1D materials and, more recently, artificial structures. They yielded direct view bands, open Fermi surfaces, and characteristic instabilities. also provided unique microscopic evidence for...
Due to their extreme surface sensitivity, the Shockley states of (111) noble metal surfaces can be used study modifications atomic and electronic properties epitaxial ultra thin films self-organized nanostructures. In metallic interfaces, different parameters state bands (energy, effective mass eventually spin–orbit splitting) have been shown strongly thickness dependent. It was also possible by scanning tunneling spectroscopy evidence a spectroscopic signature buried interfaces. Moreover,...
We report on structural and electronic properties of superconducting nanohybrids made Pb grown in the ultrahigh vacuum atomically clean surface single crystals topological Bi2Te3. In situ scanning tunneling microscopy spectroscopy demonstrated that resulting network is composed Pb-nanoislands dispersed linked together by an amorphous atomic layer Pb, which wets As a result, state system characterized thickness-dependent gap Pb-islands very unusual position-independent proximity between them....
We report on a multi-technique investigation of the supramolecular organisation N,N-diphenyl oxalic amide under differently dimensioned environments, namely three-dimensional (3D) in bulk crystal, and two dimensions Ag(111) surface as well reconstructed Au(111) surface. With help X-ray structure analysis scanning tunneling microscopy (STM) we find that molecules organize hydrogen-bonded chains with bonding motif qualitatively changed by confinement. In dimensions, exhibit enantiomorphic...
How small superconductors can be? For isolated nanoparticles subject to quantum size effects, P.W. Anderson conjectured in 1959 that superconductivity could only exist when the electronic level spacing $\delta$ is smaller than superconducting gap energy $\Delta$. Here, we report a scanning tunneling spectroscopy study of lead (Pb) nanocrystals grown on (110) surface InAs. We find for lateral Fermi wavelength 2D electron gas at InAs, transmission interface weak; this leads Coulomb blockade...
The opening of several gaps in the surface band structure vicinal Au(23 23 21) surfaces has been shown by high-resolution photoemission spectroscopy, and energy dependence electron density determined scanning tunneling spectroscopy. From a methodological point view, values phase electronic allow an estimation reconstruction potential, which yields Bragg diffraction, gap formation, modulation density. These spectroscopic behaviors give pedagogical illustration one basic concepts solid state physics.
Room-temperature deposition of Ni on Cu(111) in the submonolayer range induces growth monolayer and bilayer islands. Bilayer nanoscale islands with either or Cu surface layer are found to coexist, electronic properties which have been probed by low-temperature scanning tunneling microscopy. For both systems, a dispersive state is identified local spectroscopy, quantum interferences patterns due finite lateral size observed differential conductance mapping. Electron confinement Cu-terminated...
In materials with nearly commensurate band filling the electron liquid may spontaneously separate into components distinct properties, yielding complex intra- and interunit cell ordering patterns a reduced dimensionality. Polarization-dependent angle-resolved photoemission data submicron spatial resolution demonstrate such an electronic self-organization in ${\mathrm{NbSe}}_{3}$, compound considered to be paradigm of charge order. The new indicate emergence novel order, reveal...
Atomically thin superconductivity in Pb monolayers grown on Si(111) is affected by adding a tiny amount of Au atoms. In situ macroscopic electron transport measurements reveal that develops at higher temperatures and manifests sharper superconducting transition to zero resistance as compared pristine Pb/Si(111). Scanning tunneling microscopy spectroscopy show atoms decorate atomic step edges Pb/Si(111) link the electronic reservoirs neighboring terraces. The propagation correlations across...
By combining angle-resolved photoemission spectroscopy and scanning tunneling microscopy we reveal the structural electronic properties of multilayer graphene on Ru(0001). We prove that large ethylene exposure allows to synthesize two distinct phases bilayer with different properties. The first phase has Bernal AB stacking respect layer, displays weak vertical interaction electron doping. long-range ordered moir\'e pattern modulates crystal potential induces replicas Dirac cone minigaps....