Role of Van Hove singularities and effective mass anisotropy in polarization-resolved high harmonic spectroscopy of silicon

0568403 - FZÚ 2023 RIV DE eng J - Journal Article
Suthar, P. - Trojánek, F. - Malý, P. - Derrien, Thibault - Kozák, M.
Role of Van Hove singularities and effective mass anisotropy in polarization-resolved high harmonic spectroscopy of silicon.
COMMUNICATIONS PHYSICS. Roč. 5, č. 1 (2022), č. článku 288. ISSN 2399-3650. E-ISSN 2399-3650
R&D Projects: GA MŠMT EF15_003/0000445; GA MŠMT EF15_006/0000674
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 : high harmonic generation * TDDFT * density functional theory * Van Hove singularity * effective mass * condensed matter * ultrafast photonics
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 5.5, year: 2022
Method of publishing: Open access

Nonlinear optical response of materials exposed to strong nonresonant light fields leads to production of high energy photons whose spectra contain fingerprints of the coherent electron dynamics in the material. In this paper we investigate how the high harmonic spectra generated in crystalline silicon are linked to specific properties of its band structure. By comparing the polarization anisotropy of high harmonic spectra for two distinct frequencies of the driving pulses we show that the anisotropy has two sources. When driven by mid-infrared light, the signal at specific photon energies is enhanced by the presence of Van Hove singularities in the joint density of states of silicon. With near-infrared driving pulses, in contrast, the high harmonic yield is mainly influenced by the anisotropy of the reduced mass of electron-hole pair, which is related to the nonresonant excitation probability. The experimental results are compared with numerical calculations using time-dependent density functional theory.
Permanent Link: https://hdl.handle.net/11104/0339715