噪声下不完美量子门操作对量子加扰和受损信息恢复影响  

Effect of Imperfect Quantum Gates Operation under Noise on Quantum Scrambling and Damaged Information Recovery

作　　者：段虹晓 王川[2] 王铁军[1] DUAN Hong-xiao;WANG Chuan;WANG Tie-jun(School of Science,Beijing University of Posts and Telecommunication,Beijing 100876,China;School of Artificial Intelligence,Beijing Normal University,Beijing 100875,China)

机构地区：[1]北京邮电大学理学院,北京100876 [2]北京师范大学人工智能学院,北京100875

出　　处：《量子光学学报》2023年第4期42-54,共13页Journal of Quantum Optics

基　　金：国家自然科学基金(62071064);北京邮电大学研究生专业课程建设教改项目(2022ZY119)。

摘　　要：本文将碰撞噪声模型引入到量子加扰和受损信息恢复协议中,研究噪声引发的退相干作用对信息加扰和受损信息恢复的动力学过程的影响。结果表明噪声引发的退相干不仅会抑制信息加扰和恢复,还会提前信息恢复的时间节点。不完美controlled-NOT(CNOT)门操作会抑制信息的扩散效应,不完美Hadamard(H)门操作会对不完美CNOT门起到调制作用,从而减轻不完美CNOT门对信息扩散的抑制。通常情况下在噪声影响下的不完美CNOT门操作和不完美H门操作都会抑制信息恢复。但在某些特定参数下,两者的结合会比只施加不完美CNOT门产生更高的信息恢复率,这种奇异现象可以用来研究噪声下的量子计算过程中的信息保护,为实现高品质的量子计算过程提供新途径。Quantum scrambling is a common dynamic phenomenon in quantum information processing,which refers to initially localized information spreads over the global degrees of freedom in the system due to global entanglement resulting in local measurements failing to obtain complete information.Recent studies have found that the damaged scrambling information can be recovered through time inversion protocol.For example,by using a 4-qubits quantum circuit,Bin Yan and Nikolai Sinitsyn[Phys Rev Lett,125,0406054(2020)]simulated the damaged information recovery process of a central qubit in an environment bath of two qubits and calculated the measurement probability of the central qubit use out-of-time-ordered correlators(OTOC),and proved the possibility of damaged information recovery under time inversion with a high fidelity of 0.983 on the IBM platform.The damaged information recovery processes are crucial for protecting quantum information against environmental damage and testing the quantumness of quantum computers.The quantum scrambling and damaged information recovery process is simulated by a quantum circuit composed of perfect single-qubit gates operation and two-qubit gates operation in the above verification.However in the actual quantum evolution process,the form of real noise is more complex,and the induced decoherence process is unavoidable.There are several popular models for noise simulation such as unitary noise models and pure attenuation models,and for quantum gates operation collision models have a good approximation of the noise in reality.We import the noise of collision models to quantum gates operation in Bin Yan and Nikolai A.Sinitsyn's protocol to investigate the effect of noise-induced decoherence on the dynamical processes of information scrambling and recovery of damaged information.The introduction of decoherence noise interferes with the quantum scrambling process,decaying the out-of-time-ordered correlators and generating"false"quantum scrambling signals.So we calculate and analyze the changes o

关 键 词：量子加扰 受损信息恢复 不完美CNOT门操作 不完美H门操作 

分 类 号：O413[理学—理论物理]