增益因子对量子隐形传态保真度的影响  

Effect of Gain Factor on Fidelity of Quantum Teleportation

作　　者：闫林波 张建生[1] 董敏 姚远[1] YAN Lin-bo;ZHANG Jian-sheng;DONG Min;YAO Yuan(School of Science,Xi’an Technological University,Xi’an 710021,China)

机构地区：[1]西安工业大学基础学院,陕西西安710021

出　　处：《量子光学学报》2023年第4期11-17,共7页Journal of Quantum Optics

基　　金：陕西省重点研发计划(2023-YBGY-016);西安市未央区科技计划(201843)。

摘　　要：连续变量量子远程传态在构建连续变量量子计算以及量子信息网络中发挥着重要作用。在实际的通信过程中,由于周围环境的干扰,量子纠缠通常会和周围的环境发生相互作用,从而导致纠缠度减弱,进而影响量子信息的正确传送,导致隐形传态保真度的降低。实用的通信系统,不是简简单单地从一个点到另一个点,而是一个复杂的网络。因此利用多组份的纠缠态光场建立复杂的量子网络是必需的。本文利用四组份GHZ纠缠态光场来构建量子隐形传态网络,得出该网络系统下传送量子态的保真度公式,并仿真出不同压缩参数下增益因子对保真度的影响关系曲线,仿真结果表示:每一个确定的压缩参数都有一个最大保真度值,对于确定的压缩参数r,保真度随着增益因子的增大呈现先增大后减小的趋势。压缩参数r越大,量子态恢复的保真度越好。当增益因子取值不合适时,即使压缩参数比较大,其保真度也无法达到较高要求。Continuous-variable quantum remote state teleportation plays an important role in constructing continuous-variable quantum computing and quantum information networks.In practical communication processes,quantum entanglement typical-ly interacts with the surrounding environment due to environmental interference,resulting in a reduction of entanglement and consequently affecting the correct transmission of quantum information,leading to a decrease in the fidelity of teleportation.A practical communication system is a more complex network than a simple point-to-point connection.Therefore,it is necessary to use multipartite entangled light fields to establish complex quantum networks.In this paper,a quantum teleportation network based on four-mode GHZ entangled light fields is constructed.The fidelity formula for transmitting quantum states in this network system is derived,and simulation results show the relationship between the fidelity and the gain factor under different compression parameters.The simulations indicate that for a given compression parameter,there exists an optimal gain factor that maximizes the fidelity.The fidelity initially increases and then decreases as the gain factor increases.A larger compression parameter results in better fidelity recovery of the quantum state.However,even with a large compression parameter,the fidelity cannot reach high values if the gain factor is not properly chosen.By increasing the compression parameter r and selecting the appropriate gain factor,the fidelity can be improved.However,in the actual system,factors such as optical device loss,noise and detector performance need considering comprehensively to achieve the best transmission and detection efficiency to achieve higher fidelity.In the design and experiment,it is necessary to comprehensively consider the transmission efficiency and detection efficiency to optimize the system parameters to achieve higher fidelity.Ideally,when the squeezing parameter r approaches infinity and the gain factor achieves the optimal v

关 键 词：量子隐形传态 多组份 增益因子 保真度 纠缠态光场 

分 类 号：O413[理学—理论物理]