Preservation of Quantum Coherence for Gaussian-State Dynamics in a Non-Markovian Process
Jun Wen1,2, Guan-Qiang Li3,4**
1State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 2University of the Chinese Academy of Sciences, Beijing 100049 3School of Arts and Sciences, Shaanxi University of Science and Technology, Xi'an 710021 4Department of Applied Physics and Key Laboratory for Quantum Information and Quantum Optoelectronic Devices of Shaanxi Province, Xi'an Jiaotong University, Xi'an 710049
Abstract：Coherence is a key resource in quantum information science. Exactly understanding and controlling the variation of coherence are vital for implementation in realistic quantum systems. Using $P$-representation of density matrix, we obtain the analytical solution of the master equation for the classical states in the non-Markovian process and investigate the coherent dynamics of Gaussian states. It is found that quantum coherence can be preserved in such a process if the coupling strength between system and environment exceeds a threshold value. We also discuss the characteristic function of the Gaussian states in the non-Markovian process, which provides an inevitable bridge for the control and operation of quantum coherence.
2018, Vol. 35 
