High-order harmonic generation spectrum from two coupled Floquet resonances – a non- Hermitian formulation

0517442 - FZÚ 2020 RIV GB eng J - Článek v odborném periodiku
Kaprálová-Žďánská, Petra Ruth
High-order harmonic generation spectrum from two coupled Floquet resonances – a non- Hermitian formulation.
Molecular Physics. Roč. 117, č. 15 (2019), s. 2138-2156. ISSN 0026-8976. E-ISSN 1362-3028
Grant CEP: GA MŠMT LTT17015
GRANT EU: European Commission(XE) 654148 - LASERLAB-EUROPE
Institucionální podpora: RVO:68378271
Klíčová slova: high-order harmonic generation * non-Hermitian quantum mechanics * non-adiabatic coupling
Obor OECD: Optics (including laser optics and quantum optics)
Impakt faktor: 1.767, rok: 2019
Způsob publikování: Omezený přístup
https://doi.org/10.1080/00268976.2019.1601788

The quantity ψ(t − t/2)|ˆa|ψ(t + t/2) given for a square integrable wavefunction ψ allows one to define very different kinds of measurables, such as absorption spectrum (as a Fourier transform (FT) over t for t=0) as well as high-order harmonic generation (HHG) spectrum (as a FT over t for t=0). The main objective of this paper is to define this quantity based on a spectral decomposition of ψ to non-Hermitian wavefunctions obtained in complex scaling calculations. The obtained formal expression combines matrix elements based on the non-Hermitian c-inner product, and surprisingly also Cartesian (Euclidean) norms and overlaps of complex scaled wavefunctions. The exact non-Hermitian formalism is necessary for theoretical calculations of HHG at coupled photoionisation resonances, illustrated here for a multiphoton conversion in helium atom near a conical intersection.

Trvalý link: http://hdl.handle.net/11104/0302751