The group "Surfaces, Spectroscopies and Modeling group (SUPREME)"studies the properties of surfaces, interfaces and nanostructures. It is interested in materials with remarkable electronic properties due to their reduced dimensions at the nanometer scale, their original atomic structures, the exotic nature of their ground state, their phase change or their unique spectroscopic properties. These materials are prepared in situ by MBE or ex situ, in collaboration with partner teams. Their atomic and electronic structures are mainly studied by angle-resolved photoemission (ARPES) and microscopy / tunnel spectroscopy (STM / STS), as well as by ab initio methods based on density functional theory (DFT).
Complementary investigations are carry out on the CASSIOPEE and SIXS beamlines of the Synchrotron SOLEIL.
At the experimental level, the two complementary techniques – STM/STS – give access to the Local Density of States (LDOS) in the direct space. ARPES give access to the k-resolved band structure. All the spectroscopic measurements are done at low temperature to reach the ultimate energy resolution.
Owing to its longstanding experience in ultra-high vacuum, we elaborate ultra-thin films and nanostructured interfaces using molecular beam epitaxy (MBE).
The acquisition of a spin-ARPES set-up and a STM/STS one including the possibility to apply a magnetic field, allow probing spin-dependent electronic properties at the nanometric scale.
These materials are in situ synthetized by MBE or ex situ using standard chemical synthesis, or in collaboration with other groups in the laboratory (Intermetallic Compounds and Hybrid Materials; Materials with Thermoelectric Properties; Metallurgy and Surfaces; Materials with Thermoelectric Properties; Nanomaterials for Optics) and through national and international projects.
Besides the experimental approaches, modeling activities are carried out in the team. They are based on density functional theory. They contribute to the determination of the atomic and electronic structures of surfaces and interfaces. They deepen the understanding, at the fundamental level, of the surface properties. The systems of interest include, among other, complex intermetallic surfaces and ultra-thin films grown on a substrate, I.e. surfaces considered by our research group but also by the Metallurgy and Surfaces (203) group at IJL. These activities also benefit from several collaborations at the national and international levels.