Exact quantum dissipative dynamics under external time-dependent fields driving

TL;DR

This paper develops an efficient, exact hierarchical quantum master equation approach to model dissipative dynamics under time-dependent fields, enabling precise simulations and evaluations of perturbative methods.

Contribution

It introduces a scaled auxiliary operator scheme and an efficient propagator for hierarchical Liouville-space dynamics, improving accuracy and computational efficiency in quantum dissipation modeling.

Findings

Numerically exact dephasing effects on population transfer are demonstrated.

Assessment of perturbative theories' applicability to the studied system.

Proposed method achieves uniform error tolerance in quantum dissipative simulations.

Abstract

Exact and nonperturbative quantum master equation can be constructed via the calculus on path integral. It results in hierarchical equations of motion for the reduced density operator. Involved are also a set of well--defined auxiliary density operators that resolve not just system--bath coupling strength but also memory. In this work, we scale these auxiliary operators individually to achieve a uniform error tolerance, as set by the reduced density operator. An efficient propagator is then proposed to the hierarchical Liouville--space dynamics of quantum dissipation. Numerically exact studies are carried out on the dephasing effect on population transfer in the simple stimulated Raman adiabatic passage scheme. We also make assessments on several perturbative theories for their applicabilities in the present system of study.