Regensburg 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 11: Ultra-fast Phenomena I
HL 11.4: Vortrag
Montag, 17. März 2025, 16:45–17:00, H14
Nonequilibrium control of the ultrafast electron dynamics in semiconductors via light-driven coherent phonons — •Chenyu Wang1,2, Yaxian Wang1, and Sheng Meng1,2,3 — 1Institute of physics, Chinese Academy of Sciences — 2School of physical sciences, University of Chinese Academy of Sciences — 3Songshan Lake Materials Laboratory
Driving lattice vibration with a high degree of spatial and temporal coherence via strong light-matter interactions has emerged as a unique knob to control the out-of-equilibrium quantum states and the exotic ultrafast phenomena.
In this talk, I will present our recent theoretical works on the exploration and understanding of how the coherent phonon excitation can be utilized to control the electronic behaviors on ultrafast timescales, for example to engineer the carrier transport in monolayer WSe2 and to manipulate the nonrelativistic spin splitting in the prototypical altermagnetic semiconductor MnTe.
In photoexcited monolayer WSe2, we observe an unconventional ’step-like’ electron intervalley scattering dynamics and meanwhile a Rabi oscillation driven by the coherent phonons, as a direct manifestation of the nonadiabatic electron-phonon coupling beyond equilibrium; On the other side, we demonstrate the light-driven coherent phonon can also be utilized to break the crystal symmetry in the altermagnet MnTe. Such symmetry breaking phase holds an extra spin-splitting particularly in the zone center, and thus a strongly enhanced spontaneous anomalous Hall effect.
Keywords: coherent phonon; ultrafast phenomena; coupled electron and lattice dynamics; intervalley scattering; altermagnetism