Photoionization and transient Wannier-Stark ladder in silicon: First-principles simulations versus Keldysh theory

0561201 - FZÚ 2023 RIV US eng J - Journal Article
Derrien, Thibault - Tancogne-Dejean, N. - Zhukov, Vladimir - Appel, H. - Rubio, A. - Bulgakova, Nadezhda M.
Photoionization and transient Wannier-Stark ladder in silicon: First-principles simulations versus Keldysh theory.
Physical Review B. Roč. 104, č. 24 (2021), č. článku L241201. ISSN 2469-9950. E-ISSN 2469-9969
R&D Projects: GA MŠMT EF15_003/0000445; GA MŠMT EF15_006/0000674
EU Projects: European Commission(XE) 823897 - ATLANTIC
Grant - others:OP VVV - BIATRI(XE) CZ.02.1.01/0.0/0.0/15_003/0000445; OP VVV - HiLASE-CoE(XE) CZ.02.1.01/0.0/0.0/15_006/0000674
Research Infrastructure: e-INFRA CZ - 90140
Institutional support: RVO:68378271
Keywords : nonlinear photoionization * semiconductors * Keldysh theory * TDDFT * silicon crystal * ultrashort laser
OECD category: Optics (including laser optics and quantum optics)
Impact factor: 3.908, year: 2021
Method of publishing: Open access

Nonlinear photoionization of dielectrics and semiconductors is widely treated in the framework of the Keldysh theory whose validity is limited to photon energies that are small compared to the band gap and relatively low laser intensities. The time-dependent density functional theory (TDDFT) simulations, which are free of these limitations, enable one to gain insight into nonequilibrium dynamics of the electronic structure. Here we apply TDDFT to investigate the photoionization of silicon crystal by ultrashort laser pulses in a wide range of laser wavelengths and intensities and compare the results with predictions of the Keldysh theory. Photoionization rates derived from the simulations considerably exceed the data obtained with the Keldysh theory within the validity range of the latter. Possible reasons for the discrepancy are discussed and we provide fundamental data on the photoionization rates beyond the limits of the Keldysh theory.

Permanent Link: https://hdl.handle.net/11104/0333877