Adaptation of the Modified Adiabatic Approximation to Strong Field Ionization

TL;DR

This paper extends Savichev's modified adiabatic approximation to derive a general quantum-mechanical ionization amplitude for low-frequency laser fields, linking it with quasi-classical methods and prior research.

Contribution

It introduces a generalized form of ionization amplitude using the modified adiabatic approximation applicable to low-frequency laser fields.

Findings

Derived a general quantum ionization amplitude formula

Connected the approximation with quasi-classical methods

Discussed relations to previous studies

Abstract

Savichev's modified adiabatic approximation [Sov. Phys. JETP 73, 803 (1991)] is used to obtain a general form of a quantum-mechanical amplitude of ionization by a low-frequency laser field. The method possesses only one requirement that the frequency of the laser field must be low. Connections of the obtained result with the quasi-classical approximation and other previous investigations are discussed.