Coherent dynamics of a qubit-oscillator system in a noisy environment

TL;DR

This paper explores how non-Markovian environmental effects and strong coupling can suppress decoherence and promote coherent dynamics in a qubit-oscillator system, with implications for quantum circuit control.

Contribution

It demonstrates that increasing qubit-oscillator coupling and bath memory effects can enhance coherence and suppress decoherence in quantum systems, using hierarchical equations of motion.

Findings

Decoherence rate can be significantly suppressed by stronger qubit-oscillator coupling.

Non-Markovian bath memory facilitates robust quantum coherence.

Results suggest potential for tunable quantum manipulations in circuits.

Abstract

We investigate the non-Markovian dynamics of a qubit-oscillator system embedded in a noisy environment by employing the hierarchical equations of motion approach. It is found that the decoherence rate of the whole qubit-oscillator-bath system can be significantly suppressed by enhancing the coupling strength between the qubit and the harmonic oscillator. Moreover, we find that the non-Markovian memory character of the bath is able to facilitate a robust quantum coherent dynamics in this qubit-oscillator-bath system. Our findings may be used to engineer some tunable coherent manipulations in mesoscopic quantum circuits.