3 papers
cond-mat.mtrl-sci2026
Enhanced Valley Polarization via Nonlinear Cascaded Quantum-Geometric Selection Rules
Quentin Courtade, Sotirios Fragkos, Dominique Descamps +4
The quantum geometric properties of Bloch electrons fundamentally govern light-matter interactions and optical selection rules in solids. In semiconducting transition-metal dichalc…
cond-mat.str-el2025
Electron-phonon-dominated charge-density-wave fluctuations in TiSe accessed by ultrafast nonequilibrium dynamics
Sotirios Fragkos, Hibiki Orio, Nina Girotto Erhardt +17
The complex phase diagram of 1T-TiSe2 consists of a charge density wave (CDW) below 200 K, and CDW fluctuations of still unknown origin at higher temperatures. Here, we use time-re…
cond-mat.mtrl-sci2025
Time- and Polarization-Resolved Extreme Ultraviolet Momentum Microscopy
Sotirios Fragkos, Quentin Courtade, Olena Tkach +7
We report the development of an instrument combining an ultrafast, high-repetition-rate, polarization-tunable monochromatic extreme ultraviolet (XUV, 21.6 eV) beamline and a next-g…