Dynamics of dissipative Landau-Zener transitions

TL;DR

This paper investigates the dynamics of Landau-Zener transitions in a dissipative environment using a non-perturbative variational approach, revealing how different couplings and bath properties influence transition probabilities and boson dynamics.

Contribution

It introduces a non-perturbative variational method with multiple Davydov trial states to analyze Landau-Zener transitions with complex qubit-bath interactions.

Findings

Steady-state transition probabilities match analytical predictions.

Intermediate-time dynamics are mainly affected by off-diagonal coupling.

Bath spectral densities and interaction angles significantly influence the transitions.

Abstract

A non-perturbative treatment, the Dirac-Frenkel time-dependent variation is employed to examine dynamics of the Landau-Zener model with both diagonal and off-diagonal qubit-bath coupling using the multiple Davydov trial states. It is shown that steady-state transition probabilities agree with analytical predictions at long times. Landau-Zener dynamics at intermediate times is little affected by diagonal coupling, and is found to be determined by off-diagonal coupling and tunneling strength between two diabatic states. We investigate effects of bath spectral densities, coupling strengths and interaction angles on Laudau-Zener dynamics. Thanks to the multiple Davydov trial states, detailed boson dynamics can also be analyzed in Landau-Zener transitions. Results presented here may help provide guiding principles to manipulate the Laudau-Zener transitions in circuit QED architectures by tuning off-diagonal coupling and tunneling strength.