Optimal decoherence control of non-Markovian open quantum systems

We investigate the optimal control problem in non-Markovian open, dissipative quantum system. Optimal control using Pontryagin maximum principle of this problem has been specifically derived. The influences of Ohmic reservoir with Lorentz-Drude regularization are numerically studied in a two-level system under the following three conditions w₀ Lt w_c, w₀ ap w_c or w₀ Gt w_c respectively. The optimal control process shows its remarkable influences to the decoherence dynamics. The temperature is a key factor in the decoherence dynamics. We analysis the optimal decoherence control in high temperature, intermediate temperature, and low temperature reservoirs respectively. It implies that designing some engineered reservoirs with the controlled coupling and state of the environment can slow down the decoherence rate and delay the decoherence time. Moreover, we compared the non-Markovian optimal decoherence control with the Markovian one, we find that with non-Markovian the engineered artificial reservoirs are better than with the Markovian approximate in controlling the open, dissipative quantum systempsilas decoherence.