Analytical Approximations for Generalized Landau-Zener Transitions in Multi-level Non-Hermitian Systems

TL;DR

This paper develops analytical approximations for non-adiabatic transitions in multi-level non-Hermitian systems with quadratic energy separations, relevant for coupled cavity dynamics.

Contribution

It introduces a method to approximate wave amplitudes in complex non-Hermitian multi-level models using tri-confluent Heun functions and their reductions.

Findings

Derived analytical approximations for wave amplitudes in non-Hermitian multi-level systems.

Reduced complex dynamics to coupled tri-confluent Heun equations.

Applicable to coupled cavity systems with non-Hermitian properties.

Abstract

We study the dynamics of non-adiabatic transitions in non-Hermitian multi-level parabolic models where the separations of the diabatic energies are quadratic function of time. The model Hamiltonian has been used to describe the non-Hermitian dynamics of two pairs of coupled cavities. In the absence of the coupling between any two pairs of cavities, the wave amplitudes within each subsystem are described by the tri-confluent Heun functions. When all the couplings between the cavities are present, we reduce the dynamics into a set of two coupled tri-confluent Heun equations, from which we derive analytical approximations for the wave amplitudes at different physical limits.