›› 2014, Vol. 23 ›› Issue (12): 120305-120305.doi: 10.1088/1674-1056/23/12/120305
周并举, 彭朝晖, 贾春霞, 姜春蕾, 刘小娟
Zhou Bing-Ju (周并举), Peng Zhao-Hui (彭朝晖), Jia Chun-Xia (贾春霞), Jiang Chun-Lei (姜春蕾), Liu Xiao-Juan (刘小娟)
摘要: Considering two atomic qubits initially in Bell states, we send one qubit into a vacuum cavity with two-photon resonance and leave the other one outside. Using quantum information entropy squeezing theory, the time evolutions of the entropy squeezing factor of the atomic qubit inside the cavity are discussed for two cases, i.e., before and after rotation and measurement of the atomic qubit outside the cavity. It is shown that the atomic qubit inside the cavity has no entropy squeezing phenomenon and is always in a decoherent state before the operating atomic qubit outside the cavity. However, the periodical entropy squeezing phenomenon emerges and the optimal entropy squeezing state can be prepared for the atomic qubit inside the cavity by adjusting the rotation angle, choosing the interaction time between the atomic qubit and the cavity, controlling the probability amplitudes of subsystem states. Its physical essence is cutting the entanglement between the atomic qubit and its environment, causing the atomic qubit inside the cavity to change from the initial decoherent state into maximum coherent superposition state, which is a possible way of recovering the coherence of a single atomic qubit in the noise environment.
中图分类号: (Entanglement and quantum nonlocality)