Investigation of decoherence of superconducting charge qubit entangled with the environment

In the Born-Markov approximation, a method that calculates the energy relaxation time T-1 and the decoherence time T-2 of superconducting qubits is given by solving the set of Bloch-Redfield equations and considering the results of decoherence of a superconducting charge qubit. Compared to the spin-boson model, it not only contains the decoherence being caused by the dissipative environment, but also includes the decoherence being generated by the dissipative elements in a superconducting electronic circuit. Hence, it is good for studying the decoherence of superconducting qubits comprehensively.