Qubit coupled with an effective negative-absolute-temperature bath in off-resonant collision model

TL;DR

This paper investigates a qubit coupled to an effective negative-absolute-temperature bath within an off-resonant collision model, revealing unique dynamics and constraints that differ from resonant regimes, with potential applications in thermal device development.

Contribution

It establishes and analyzes an effective negative-absolute-temperature bath coupled to a qubit in a far-off-resonant collision model, expanding understanding of off-resonant quantum dynamics.

Findings

Distinct dynamics in off-resonant regime compared to resonant cases

Additional constraints on collision duration due to off-resonance

Numerical simulations validate the proposed model

Abstract

Quantum collision model provides a promising tool for investigating system-bath dynamics. Most of the studies on quantum collision models work in the resonant regime. In quantum dynamics, the off-resonant interaction often brings in exciting ffects. It is thereby attractive to investigate quantum collision models in the off-resonant regime. On the other hand, a bath with a negative absolute temperature is anticipated to be instrumental in developing thermal devices. The design of an effective bath with negative absolute temperature coupled to a qubit is significant for developing such thermal devices. We establish an effective negative-absolute-temperature bath coupled to a qubit with a quantum collision model in a far-off-resonant regime. We conduct a detailed and systematic investigation on the off-resonant collision model. There is an additional constraint on the collision duration resulting from the far-off resonant collision. The dynamics of the collision model in the far-off-resonant regime are different from the one beyond the far-off-resonant regime. Numerical simulations confirm the validity of the proposed approach.