We investigate how the correlated actions of quantum channels affect the robustness of entangled states.We consider the Bell-like state and random two-qubit pure states in the correlated depolarizing,bit flip,bit-phas...We investigate how the correlated actions of quantum channels affect the robustness of entangled states.We consider the Bell-like state and random two-qubit pure states in the correlated depolarizing,bit flip,bit-phase flip,and phase flip channels.It is found that the robustness of two-qubit pure states can be noticeably enhanced due to the correlations between consecutive actions of these noisy channels,and the Bell-like state is always the most robust one.We also consider the robustness of three-qubit pure states in correlated noisy channels.For the correlated bit flip and phase flip channels,the result shows that although the most robust and most fragile states are locally unitary equivalent,they exhibit different robustness in different correlated channels,and the effect of channel correlations on them is also significantly different.However,for the correlated depolarizing and bit-phase flip channels,the robustness of two special three-qubit pure states is exactly the same.Moreover,compared with the random three-qubit pure states,they are neither the most robust states nor the most fragile states.展开更多
We show that for Green-Schwarz superstring in AdS_(3)×S^(3),the one-parameter family of flat currents retains a zero-curvature condition and keeps the variation relations under is-symmetry,diffeomorphism,local Lo...We show that for Green-Schwarz superstring in AdS_(3)×S^(3),the one-parameter family of flat currents retains a zero-curvature condition and keeps the variation relations under is-symmetry,diffeomorphism,local Lorentz SO(1,2)×SO(3)and global PSU(1,1|2)^(2)symmetry transformations respectively.This indicates that the flat currents exist in all the n-symmetry gauge fixed cases.As a result,we find that the infinite conserved quantities are invariant under these transformations and independent of the gauge choice of the system.展开更多
We parameterize the Green–Schwarz IIB superstring in the AdS_(3)×S^(3) background under the light cone gauge by the method of Metsaev and Tseytlin in AdS3 and by the method of Rahmfeld and Rajaraman in S3.After ...We parameterize the Green–Schwarz IIB superstring in the AdS_(3)×S^(3) background under the light cone gauge by the method of Metsaev and Tseytlin in AdS3 and by the method of Rahmfeld and Rajaraman in S3.After some calculation,we obtain the corresponding Maurer–Cartan 1−forms and the action.Then we fix two bosonic variables x+=τand y^(5)=σ,perform the partial Legendre transformation of the remaining bosonic variables,and find a Lagrangian that is linear in velocity after eliminating the metric of the world sheet.We also give the Hamiltonian and prove that the system is local and the Poisson bracket of the theory can be well defined.Using these results,one can further study the properties of solution space,solution transformation and the structure of the flat current algebra of the superstring in the AdS_(3)×S^(3) background.展开更多
We perform a Hamiltonian analysis of the Green-Schwarz sigma model on a supercoset target with Z4m grading. The fundamental Poisson brackets between the spatial component of the flat currents depending on a continuous...We perform a Hamiltonian analysis of the Green-Schwarz sigma model on a supercoset target with Z4m grading. The fundamental Poisson brackets between the spatial component of the flat currents depending on a continuous parameter, which can be thought of as a first step in the complete calculation of the algebra of the transition matrices, are obtained. When m = 1, our results are reduced to the results of the type IIB Green-Schwarz superstring on AdS5×S5 background obtained by Das, Melikyan and Sato.展开更多
We have studied Yang-Baxter deformations of supercoset sigma models with Z4m grading.The deformations are specified by a skew-symmetric classical r-matrix satisfying the classical Yang-Baxter equations.The deformed ac...We have studied Yang-Baxter deformations of supercoset sigma models with Z4m grading.The deformations are specified by a skew-symmetric classical r-matrix satisfying the classical Yang-Baxter equations.The deformed action is constructed and the Lax pair is also presented.When m= 1,our results reduce to those of the type ⅡB Green-Schwarz superstring on AdS5×S5 background recently given by Kawaguchi,Matsumoto and Yoshida.展开更多
基金the National Natural Science Foundation of China(Grant Nos.11705146 and 12175179)the Natural Science Basic Research Program of Shaanxi Province,China(Grant No.2019JQ-863)the Open Project of Shaanxi Key Laboratory for Theoretical Physics Frontiers(Grant No.SXKLTPF-K20190606)。
文摘We investigate how the correlated actions of quantum channels affect the robustness of entangled states.We consider the Bell-like state and random two-qubit pure states in the correlated depolarizing,bit flip,bit-phase flip,and phase flip channels.It is found that the robustness of two-qubit pure states can be noticeably enhanced due to the correlations between consecutive actions of these noisy channels,and the Bell-like state is always the most robust one.We also consider the robustness of three-qubit pure states in correlated noisy channels.For the correlated bit flip and phase flip channels,the result shows that although the most robust and most fragile states are locally unitary equivalent,they exhibit different robustness in different correlated channels,and the effect of channel correlations on them is also significantly different.However,for the correlated depolarizing and bit-phase flip channels,the robustness of two special three-qubit pure states is exactly the same.Moreover,compared with the random three-qubit pure states,they are neither the most robust states nor the most fragile states.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10575080 and 11047179the NWU Graduate Cross-discipline Funds(09YJC25)+1 种基金the Youth Foundation of Xi’an Institute of Posts and Telecommunications(ZL2007-18)the Special Fund for Basic Scientific Research of Central Colleges,Chang’an University and supported by the Special Foundation for Basic Research Program of Chang’an University,Open Fund of Key Laboratory for Special Area Highway Engineering(Chang’an University)(Ministry of Education)under Grant No CHD2009JC030.
文摘We show that for Green-Schwarz superstring in AdS_(3)×S^(3),the one-parameter family of flat currents retains a zero-curvature condition and keeps the variation relations under is-symmetry,diffeomorphism,local Lorentz SO(1,2)×SO(3)and global PSU(1,1|2)^(2)symmetry transformations respectively.This indicates that the flat currents exist in all the n-symmetry gauge fixed cases.As a result,we find that the infinite conserved quantities are invariant under these transformations and independent of the gauge choice of the system.
基金by the National Natural Science Foundation of China under Grant Nos 11047179,11075126,11031005 and 10575080the Special Fund for Basic Scientific Research of Central Colleges,Chang’an University+4 种基金the Special Foundation for Basic Research Program of Chang’an Universitythe Open Fund of Key Laboratory for Special Area Highway Engineering(Chang’an University)the Ministry of Education under Grant No CHD2009JC030the Xi’an Shiyou University Science and Technology Foundation under Grant No 2010QN018the NWU Graduate Cross-Discipline Funds under Grant No 09YJC25.
文摘We parameterize the Green–Schwarz IIB superstring in the AdS_(3)×S^(3) background under the light cone gauge by the method of Metsaev and Tseytlin in AdS3 and by the method of Rahmfeld and Rajaraman in S3.After some calculation,we obtain the corresponding Maurer–Cartan 1−forms and the action.Then we fix two bosonic variables x+=τand y^(5)=σ,perform the partial Legendre transformation of the remaining bosonic variables,and find a Lagrangian that is linear in velocity after eliminating the metric of the world sheet.We also give the Hamiltonian and prove that the system is local and the Poisson bracket of the theory can be well defined.Using these results,one can further study the properties of solution space,solution transformation and the structure of the flat current algebra of the superstring in the AdS_(3)×S^(3) background.
基金Supported by National Natural Science Foundation of China (11047179, 11075126, 11031005)Special Fund for Basic Scientific Research of Central Colleges, Chang’an University, Special Foundation for Basic Research Program of Chang’an University, Open Fund of Key Laboratory for Special Area Highway Engineering (Chang’an University), Ministry of Education (CHD2009JC030)Xi’an Shiyou University Science and Technology Foundation (2010QN018)
文摘We perform a Hamiltonian analysis of the Green-Schwarz sigma model on a supercoset target with Z4m grading. The fundamental Poisson brackets between the spatial component of the flat currents depending on a continuous parameter, which can be thought of as a first step in the complete calculation of the algebra of the transition matrices, are obtained. When m = 1, our results are reduced to the results of the type IIB Green-Schwarz superstring on AdS5×S5 background obtained by Das, Melikyan and Sato.
基金Supported by National Natural Science Foundation of China(11375141,11425522,11547050)Natural Science Foundation of Shaanxi Province(2013JQ1011,2017ZDJC-32,2016JM1027)+3 种基金Special Foundation for Basic Scientific Research of Central Colleges(310812152001,310812172001,2013G1121082,CHD2012JC019)Scientific Research Program Funded by Shaanxi Provincial Education Department(2013JK0628)Xi’an Shiyou University Science and Technology Foundation(2010QN018)partly supported by the Basic Research Foundation of Engineering University of CAPF(WJY-201506)
文摘We have studied Yang-Baxter deformations of supercoset sigma models with Z4m grading.The deformations are specified by a skew-symmetric classical r-matrix satisfying the classical Yang-Baxter equations.The deformed action is constructed and the Lax pair is also presented.When m= 1,our results reduce to those of the type ⅡB Green-Schwarz superstring on AdS5×S5 background recently given by Kawaguchi,Matsumoto and Yoshida.
