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

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 shown 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.