N=4自旋链上量子信息在弱磁场中的传输研究
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摘要
基于量子信息在自旋链上的传输理论,研究了两种磁场情形下N=4的自旋链上单比特量子信息传输受到的影响.对置于磁场中的自旋链,将体系的哈密顿算符进行对角化,进而考虑磁场中信息传输的动力学行为.结果表明空间均匀、时间恒定的弱磁场不会对该模型中量子信息的传输产生任何影响;各格点处大小逐差为B、方向关于链中心对称的弱磁场对量子信息的传输有至关重要的作用.尤其是对于保真度为1的完美传输,磁场参量B很大程度上决定了传输得以实现的条件.
Based on the theory of quantum information transfer in spin chain, the effects of two types of magnetic field are investigated for a single qubit information transfer in spin chain with N= 4. For the spin chain in magnetic fields, Hamiltonian of the system is diagonalized,and the dynamic behavior of information transfer is considered in magnetic field. Results show that the low-intensity magnetic field which is uniform in space and constant in time has nothing to do with quantum information transfer.The low-intensity magnetic field with the difference value B between the nearest-neighbor lattices and the symmetrical direction to center of the spin chain plays a key role for quantum information transfer.Particularly, for the perfect transfer with fidelity value of 1, the transferring condition is dependent on the magnetic parameter B to a great extent.
Based on the theory of quantum information transfer in spin chain, the effects of two types of magnetic field are investigated for a single qubit information transfer in spin chain with N= 4. For the spin chain in magnetic fields, Hamiltonian of the system is diagonalized,and the dynamic behavior of information transfer is considered in magnetic field. Results show that the low-intensity magnetic field which is uniform in space and constant in time has nothing to do with quantum information transfer.The low-intensity magnetic field with the difference value B between the nearest-neighbor lattices and the symmetrical direction to center of the spin chain plays a key role for quantum information transfer.Particularly, for the perfect transfer with fidelity value of 1, the transferring condition is dependent on the magnetic parameter B to a great extent.
引文
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[11]Wang Qingliang,Ren Hengfeng.Influence of low-intensity magnetic field on quantum information transfer in N=3 spin chain[J].Chinese Journal of Quantum Electronics(量子电子学报),2016,33(6):724-728(in Chinese).
[2]Christandl M,Datta N,Ekert A,et al.Perfect state transfer in quantum spin networks[J].Physical Review Letters,2004,92(18):187902.
[3]Benjamin S C,Bose S.Quantum computing with an always-on Heisenberg interaction[J].Physical Review Letters,2003,90(24):247901.
[4]Christandl M,Datta N,et al.Perfect transfer of arbitrary states in quantum spin networks[J].Physical Review A,2005,71(3):032312.
[5]Ronke R,Spiller T P,DAmic I.Effect of perturbations on information transfer in spin chains[J].Physical Review A,2011,83(1):012325.
[6]Ajoy A,Cappellaro P.Mixed-state quantum transport in correlated spin networks[J].Physical Review A,2012,85(4):042305.
[7]Huang Y C,Moore J E.Excited-state entanglement and thermal mutual information in random spin chains[J].Physical Review B,2014,90(22):220202(R).
[8]Chen J L,Wang Q L.Perfect transfer of entangled states on spin chain[J].International Journal of Theoretical Physics,2007,46(3):614-624.
[9]Rafiee M,Lupo C,Mancini S.Noise to lubricate qubit transfer in a spin network[J].Physical Review A,2013,88(3):032325.
[10]Cai Yin,Feng J L,Wang H L,et al.Quantum-network generation based on four-wave mixing[J].Physical Review A,2015,91(1):013843.
[11]Wang Qingliang,Ren Hengfeng.Influence of low-intensity magnetic field on quantum information transfer in N=3 spin chain[J].Chinese Journal of Quantum Electronics(量子电子学报),2016,33(6):724-728(in Chinese).