Regensburg 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 99: Ultrafast Electron Dynamics IV
O 99.2: Vortrag
Freitag, 21. März 2025, 10:45–11:00, H11
Giant acceleration of polaron transport by ultrafast laser-induced coherent phonon — •Huimin Wang1,2, Xinbao Liu1,2, Shiqi Hu1,2, Daqiang Chen1,2, Qing Chen1,2, Cui Zhang1,3, Mengxue Guan1,2, and Sheng Meng1,2,3 — 1Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China. — 2School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China. — 3Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
Polaron formation is ubiquitous in polarized materials, but severely hampers carrier transport for which effective controlling methods are urgently needed. Here, we show that laser-controlled coherent phonon excitation enables orders of magnitude enhancement of carrier mobility via accelerating polaron transport in a prototypical material, lithium peroxide (Li2O2). The selective excitation of specific phonon modes, whose vibrational pattern directly overlap with the polaronic lattice deformation, can remarkably reduce the energy barrier for polaron hopping. The strong nonadiabatic couplings between the electronic and ionic subsystem play a key role in triggering the migration of polarons, via promoting phonon-phonon scattering within sub-picoseconds. These results extend our understanding of polaron transport dynamics to the non-equilibrium regime and allow for optoelectronic devices with ultrahigh on-off ratio and ultrafast responsibility, competitive with those of state-of-the-art devices fabricated based on free electron transport. H.M.Wang et al. Sci.Adv.9,eadg3833(2023).
Keywords: Non-equilibrium dynamics; Electron-phonon interactions; Polaron; Non-adiabatic molecular dynamics; Time-dependent density functional theory