7 papers · 1 filter
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…
Dielectric Screening in Electromagnetic Dressing of Semiconductors
Quentin Courtade, Umberto Dellasette, Sotirios Fragkos +4
Nonequilibrium manipulation of quantum materials via electromagnetic dressing provides an on-demand route to tailoring electronic band structures through Floquet engineering. Time-…
Symmetry-Driven Floquet Engineering in Multivalley SnS
Sotirios Fragkos, Benshu Fan, Umberto De Giovannini +5
Coherent interactions between time-periodic electromagnetic fields and materials offer a powerful platform for engineering light-matter hybrid Floquet states with tailored function…
Ultrafast Strongly Anisotropic Valleytronics in SnSe
Yiming Pan, Sotirios Fragkos, Dominique Descamps +3
Valleytronics aims to control electrons in a valley-specific manner for quantum information manipulation. Due to their strong in-plane anisotropy, which enables polarization-contro…
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…
Excited States Band Mapping and Ultrafast Nonequilibrium Dynamics in Topological Dirac Semimetal 1T-ZrTe
Sotirios Fragkos, Evgenia Symeonidou, Emile Lasserre +7
We performed time- and polarization-resolved extreme ultraviolet momentum microscopy on topological Dirac semimetal candidate 1T-ZrTe. Excited states band mapping uncovers the…