Resonant interactions of diatomic molecules with intense laser fields: time-independent multi-channel Green function theory and application to experiment

Matrix technique for nonperturbative Green function of time-independent Schrödinger equation

“…The quasi-classical functions obtained above may be used, if the conditions equations (41), (46) are fulfilled. It can be proved for the example of resonant molecular photoprocesses, that the analytic equations for the amplitudes of quantum transitions, received with the quasi-classical functions, are true even beyond the quasi-classical approximation (see review [12] and references therein).…”

“…The general expressions for GF, obtained in this section, are important for physics applications, because they permit to calculate analytically the quantum transition probabilities without perturbative restrictions upon the inter-channel interaction (few examples see in [1,12,13,5]). …”

“…In the case of strong couplings, where the inter-channel interaction is comparable with energy gap between the unperturbed quantum states, the perturbation theory is inapplicable and one has to study the total Hamiltonian beyond a perturbative approach. In theoretical applications it is important to have the GF of the nonperturbative Hamiltonian in order to obtain a multi-channel propagator and transition probability (see, for example, [1,12]). …”

Light-induced molecular potentials and temperature-dependent polarization of molecular vapours in intense resonant laser fields: I. Nonperturbative theory in quasi-classical approximation

“…v JM pX ðR; N Þ depends on internuclear distance and is the full quantum-electrodynamic wavefunction of the nuclear motion in the set of intersecting electronic-rotation molecular terms dressed by the laser field (see [8] for details). The electronic-rotation basis function hn a |pJMXi is the following product of the Wigner function D J MX ðã;b; 0Þ, describing the molecular rotations (ã;b;c are the Euler angles of the molecular axis onto the space-fixed frame), and the relativistic wavefunction of molecular electrons U ðeÞ pX ðR; y i ; r i Þ:…”

“…In the laser fields of moderate intensity, 10 8 W/cm 2 < I < 10 10 W/cm 2 , neither perturbation theory nor adiabatic perturbation theory may be applied and various numerical approaches are widely in use [5][6][7]. Several years ago, it had also been demonstrated that all the three above-mentioned domains of laser intensity could be simply treated within an universal multi-channel analytic approach [8].…”