Electron-ion coupling in semiconductors beyond Fermi's golden rule

0503539 - ÚFP 2019 RIV US eng J - Článek v odborném periodiku
Medvedev, Nikita - Li, Z. - Tkachenko, V. - Ziaja, B.
Electron-ion coupling in semiconductors beyond Fermi's golden rule.
Physical Review B. Roč. 95, č. 1 (2017), č. článku 014309. ISSN 2469-9950. E-ISSN 2469-9969
Grant CEP: GA MŠMT LG15013; GA MŠMT(CZ) LM2015083
Institucionální podpora: RVO:61389021
Klíčová slova: warm dense matter * elaxation-time approximation * Lindhard dielectric function * femtosecond laser-pulses * duration monitor * fel-pulse
Obor OECD: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Impakt faktor: 3.813, rok: 2017
http://bib-pubdb1.desy.de/record/317676/files/PhysRevB.95.014309.pdf

In the present work, a theoretical study of electron-phonon (electron-ion) coupling rates in semiconductors driven out of equilibrium is performed. Transient change of optical coefficients reflects the band gap shrinkage in covalently bonded materials, and thus, the heating of atomic lattice. Utilizing this dependence, we test various models of electron-ion coupling. The simulation technique is based on tight-binding molecular dynamics. Our simulations with the dedicated hybrid approach (XTANT) indicate that the widely used Fermi's golden rule can break down describing material excitation on femtosecond time scales. In contrast, dynamical coupling proposed in this work yields a reasonably good agreement of simulation results with available experimental data.
Trvalý link: http://hdl.handle.net/11104/0295356