Controlling Decoherence from Fluctuating Magnetic Field

A different strategy is proposed to control decoherence from fluctuating magnetic field by adjusting external controllable parameters. The results show that the output states in terms of the fidelity are pure states, which correspond to the state vectors that are given by a renormalized Hamiltonian. Thus, the output states may perfectly preserve memory of initial single-qubit states at some critical magnetic field parameters.