Effect of bath temperature on the quantum decoherence

TL;DR

This paper theoretically examines how bath temperature influences quantum decoherence in a qubit across two different environments, revealing environment-dependent effects of temperature on decoherence rates.

Contribution

It provides a comparative analysis of temperature effects on qubit decoherence in two distinct environments using a unitary transformation approach, highlighting environment-specific behaviors.

Findings

Decoherence can be reduced with increasing temperature in a two-level system coupled to a bosonic bath.

Decoherence cannot be reduced with temperature in a damped harmonic oscillator environment.

Qubit dynamics are significantly affected by coupling strength and finite detuning.

Abstract

The dynamics of a qubit in two different environments are investigated theoretically. The first environment is a two level system coupled to a bosonic bath. And the second one is a damped harmonic oscillator. Based on a unitary transformation, we find that the decoherence of the qubit can be reduced with increasing temperature $T$ in the first case, which agree with the results in [Phys. Rev. Lett. 100, 120401], whereas, it can not be reduced with $T$ in the second case. In both cases, the qubit dynamics are changed substantially as the coupling increases or finite detuning appears.