Quantum deleting and cloning in a pseudo-unitary system  

作　　者：Yu-Cheng Chen Ming Gong Peng Xue Hai-Dong Yuan Cheng-Jie Zhang 

机构地区：[1]School of Physical Science and Technology,Ningbo University,Ningbo,315211,China [2]Key Laboratory of Quantum Information,University of Science and Technology of China,CAS,Hefei,230026,China [3]Beijing Computational Science Research Center,Beijing,100084,China [4]Department of Mechanical and Automation Engineering,The Chinese University of Hong Kong,Hong Kong,China [5]School of Physical Science and Technology,Soochow University,Suzhou,215006,China

出　　处：《Frontiers of physics》2021年第5期61-67,共7页物理学前沿（英文版）

基　　金：This work was funded by the National Natural Science Foundation of China(Grant Nos.11734015,11474049,and 11674056);the K.C.Wong Magna Fund in Ningbo University,the financial support from Research Grants Council of Hong Kong(RGC,Hong Kong)(Grant No.538213);M.G.was supported by the National Youth Thousand Talents Program(Grant No.KJ2030000001);the USTC start-up funding(Grant No.KY2030000053).

摘　　要：In conventional quantum mechanics,quantum no-deleting and no-cloning theorems indicate that two different and nonorthogonal states cannot be perfectly and deterministically deleted and cloned,respectively.Here,we investigate the quantum deleting and cloning in a pseudo-unitary system.We first present a pseudo-Hermitian Hamiltonian with real eigenvalues in a two-qubit system.By using the pseudo-unitary operators generated from this pseudo-Hermitian Hamiltonian,we show that it is possible to delete and clone a class of two different and nonorthogonal states,and it can be generalized to arbitrary two different and nonorthogonal pure qubit states.Furthermore,state discrimination,which is strongly related to quantum no-cloning theorem,is also discussed.Last but not least,we simulate the pseudo-unitary operators in conventional quantum mechanics with post-selection,and obtain the success probability of simulations.Pseudo-unitary operators are implemented with a limited efficiency due to the post-selections.Thus,the success probabilities of deleting and cloning in the simulation by conventional quantum mechanics are less than unity,which maintain the quantum no-deleting and no-cloning theorems.

关 键 词：quantum deleting quantum cloning pseudo-unitary 

分 类 号：O41[理学—理论物理]