Zhang Ying-Jie, Han Wei, Xia Yun-Jie, Tian Jian-Xiang, Fan Heng
Shandong Provincial Key Laboratory of Laser Polarization and Information Technology, Department of Physics, Qufu Normal University, Qufu 273165, China.
Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Sci Rep. 2016 Jun 10;6:27349. doi: 10.1038/srep27349.
As is well known, quantum speed limit time (QSLT) can be used to characterize the maximal speed of evolution of quantum systems. We mainly investigate the QSLT of generalized N-qubit GHZ-type states and W-type states in the amplitude-damping channels. It is shown that, in the case N qubits coupled with independent noise channels, the QSLT of the entangled GHZ-type state is closely related to the number of qubits in the small-scale system. And the larger entanglement of GHZ-type states can lead to the shorter QSLT of the evolution process. However, the QSLT of the W-type states are independent of the number of qubits and the initial entanglement. Furthermore, by considering only M qubits among the N-qubit system respectively interacting with their own noise channels, QSLTs for these two types states are shorter than in the case N qubits coupled with independent noise channels. We therefore reach the interesting result that the potential speedup of quantum evolution of a given N-qubit GHZ-type state or W-type state can be realized in the case the number of the applied noise channels satisfying M < N.
众所周知，量子速度极限时间（QSLT）可用于表征量子系统演化的最大速度。我们主要研究广义N量子比特GHZ型态和W型态在振幅衰减信道中的QSLT。结果表明，在N个量子比特与独立噪声信道耦合的情况下，纠缠GHZ型态的QSLT与小规模系统中的量子比特数密切相关。并且GHZ型态越大的纠缠度可导致演化过程的QSLT越短。然而，W型态的QSLT与量子比特数和初始纠缠度无关。此外，通过分别考虑N量子比特系统中仅M个量子比特与其自身的噪声信道相互作用，这两种类型态的QSLT比N个量子比特与独立噪声信道耦合的情况更短。因此，我们得到了一个有趣的结果，即在应用噪声信道数满足M < N的情况下，可以实现给定N量子比特GHZ型态或W型态的量子演化的潜在加速。
