Laboratoire de Physique et d'Étude des Matériaux

Rare-Earth-Doped Materials : From Photon Conversion to Emerging Applications

Sergei Kozlov — 2026-06-18T07:42:16Z

Thursday, June 25, at 2:00 pm (Paris time) Room Charpak, 10 rue Vauquelin, ESPCI
Quantum Cutting in Ytterbium-Doped Solution-Processed Metal Halide Perovskites Films
Antoine Kahn Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ 08544, USA
Quantum cutting is a potential strategy to mitigate thermalization losses in solar cells.1,2 Our focus is on films of Ytterbium (Yb)-doped CsPb(Cl1-xBrx)3, a metal halide perovskite that absorbs visible light and (…)

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Antonio García-Martín Instituto de Micro y Nanotecnología IMN-CNM, CSIC, Madrid, Spain

Sergei Kozlov — 2026-06-04T15:25:33Z

Thursday, June 11, at 2:00 pm (Paris time) Room Boreau, building C, 2nd floor, 10 rue Vauquelin, ESPCI
Nanophotonic Metasurfaces : VO2 Phase Control and qBIC-Enhanced Non-Reciprocity
In this presentation I will address engineered metasurfaces involving external tuning via vanadium dioxide (VO2) and non-reciprocal enhancement via quasi-bound states in the continuum (qBICs). VO2 exhibits a notable insulator-to-metal transition at 68°C with a dramatic change in electrical resistivity, (…)

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Adriano Amaricci, CNR, Trieste, Italy

Sergei Kozlov — 2026-05-29T06:55:45Z

Thursday, June 4, at 2:00 pm (Paris time) Room Holweck, building C, 1st floor, 10 rue Vauquelin, ESPCI
Strongly correlated exciton-polarons in twisted homobilayer heterostructures
We consider dressing of excitonic properties by strongly correlated electrons in gate-controlled twisted homo-bilayer heterostructures, as analyzed in recent experiments. The combined effect of the moiré potential and the Coulomb interaction supports the formation of different strongly correlated phases which (…)

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Marko Kralj, Institute of Physics, Bijenička 46, Zagreb, Croatia

Sergei Kozlov — 2026-05-22T13:18:20Z

Thursday, May 28 , at 2:00 pm (Paris time) Room Holweck, building C, 1st floor, 10 rue Vauquelin, ESPCI
Epitaxial Growth of Next-Generation 2D Materials
Long before graphene gained fame in 2004, its epitaxial growth had already been realized in surface science studies focused on the adsorption and decomposition of hydrocarbons on metal substrates [1]. Surface parameters play a crucial role in the synthesis of various two-dimensional (2D) materials, including graphene, transition metal (…)

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Sergio Caprara, Department of Physics, University of Rome Sapienza

Sergei Kozlov — 2026-05-18T07:39:42Z

Friday, May 22, at 2:00 pm (Paris time)
Room Charpak
Shrinking Fermi Liquid and Strange Metal behavior from Charge Density Fluctuations in superconducting cuprates
I shall discuss a proposal that attributes the strange metallic behavior of cuprates to the occurrence of very slow dynamical charge density fluctuations in these systems. These excitations have indeed been detected by means of resonant inelastic X-ray scattering. The main consequence of their slow dynamics is to endow the (…)

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Victor Brar Department of Physics, University of Wisconsin–Madison, Madison, Wisconsin, USA

Sergei Kozlov — 2026-05-13T13:38:01Z

May 21 at 2:00 pm (Paris time) Room Charpak
Imaging charge carrier dynamics and phase transitions using scanning probe potentiometry
I will discuss how scanning tunneling potentiometry (STP) can be used to measure the electrochemical profile of current-biased graphene as the quasiparticles transition through different electronic phases. I will first describe how STP maps relate to local current density distribution of a sample. I will then demonstrate how the scanned probe tip can be (…)

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Guillaume F. Nataf GREMAN UMR7347, CNRS, University of Tours, INSA Centre Val de Loire, 37000 Tours, France

Sergei Kozlov — 2026-05-07T10:24:42Z

May 7 at 2:00 pm (Paris time) Room Charpak
Control of thermal conductivity in ferroelectric and ferroelastic materials
Since the early days of computing, hardware has evolved from mechanical to digital systems, where logic operations are performed by controlling electrons in semiconductors. However, the development of semiconductor-based chips is encountering important bottlenecks. To be disruptive, future progress is expected to be driven by different information carriers. Here, we (…)

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Michal Šindler, FZU, Institute of Physics of the Czech Academy of Sciences, Czech Republic

Sergei Kozlov — 2026-04-11T07:31:52Z

April 16 at 2:00 pm (Paris time)
Room Charpak, entrance building, ground floor
Terahertz spectroscopy of thin NbN films
Terahertz (THz) spectroscopy offers unique access to the key properties of superconductors, such as the superconducting gap, penetration depth, quasiparticle behavior, vortex dynamics, and non-equilibrium relaxation. I will illustrate the advantages and limitations of this approach through our previous work on high-quality thin NbN films showcasing measurements from (…)

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Florian Le Mardelé, Laboratoire national des champs magnétiques intenses, Toulouse

Sergei Kozlov — 2026-03-27T13:39:41Z

April 3 at 2:00 pm (Paris time) Room Charpak, entrance building, ground floor
Magneto-optical spectroscopy on van-der-Waals antiferromagnets and topological semimetals
Magneto-optical spectroscopy focuses on the interaction between light and matter,with the magnetic field acting as a continuously adjustable external parameter. The magneto-optic response offers valuable information into the intrinsic properties of systems in their unperturbed states. As a historical example, Landau-level (…)

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Ludovica Zullo, Wuerzburg University

Sergei Kozlov — 2026-03-12T17:23:34Z

March 19 at 2:00 pm (Paris time) Room Holweck, building C, 1st floor
The power of flatness : an ab initio guide to tunable flat bands in 2D materials
In condensed matter, flatness is anything but boring : when a band's energy dispersion becomes nearly flat, electrons lose their kinetic identity and correlations take over, giving rise to exotic physics. In this talk, I will show how to design two-dimensional materials in which flat bands may be engineered and tuned through experimentally (…)

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