Decoherence Dynamics of a Superconducting Charge Qubit Coupled to a Boson Bath and a Spin Bath

By virtue of a superconducting charge qubit, we derive the off-diagonal matrix operator and investigate the decoherence of the system in different regimes coupled to, respectively, the boson bath and the spin bath. It is found that the two different baths make a bit of difference on the decay of the system at low but finite temperature and the decoherence of the system is most closely linked with the regime as well as the coupling strength. Therefore, by optimizing some reasonable parameters, we can suppress appropriately the decoherence of a given quantum system.