Energy Transport Induced by Transition from Weak to Strong Coupling Regime Between Non-Hermitian systems

TL;DR

This paper investigates how energy transport between non-Hermitian systems changes during the transition from weak to strong coupling, revealing a maximum in normalized energy flow at the transition point.

Contribution

It introduces a partial-secular approach to analyze energy transport during the coupling transition in open quantum systems, highlighting the maximum energy flow at the transition.

Findings

Energy flow peaks near the transition point between coupling regimes.

Normalized energy flow reaches maximum at zero and non-zero detuning.

High relaxation suppresses energy flow.

Abstract

Recently, strong coupling between non-Hermitian physical systems of different nature is widely investigated due to it endows them with new properties. In this work, we investigate the energy transport between strongly coupled systems. We use a partial-secular approach for the description of an open quantum system to investigate the system dynamics during the transition from a weak to a strong coupling regime with an increase of coupling between subsystems. On the example of strongly coupled two-level atoms, we show that near the transition point enhancement of energy transport between the system and reservoirs takes place. This manifests in the fact that energy flow normalized to the coupling constant reaches the maximum both in the cases of zero and non-zero frequency detuning. We show that maximization of normalized energy flow can be used for the determination of the transition to the strong coupling regime in the case of non-zero detuning when there is no clear transition point from the weak to strong coupling regime. The suppression of the energy flow at high relaxation is demonstrated.