基于单比特量子信息在自旋链上的完美传输理论,研究了2种不随时变化的弱磁场 对N=3的自旋链上单比特量子信息完美传输的影响。对包含磁场体系的哈密顿量进行对角化,并 考虑演化算子的作用,结果表明:空间均匀且不随时变化的恒定弱磁场不会对信息传输的保真 度产生影响;大小关于中心对称、方向相反的弱磁场直接影响了实现量子信息完美传输的条件, 磁场越强实现完美传输的时间越短。

Based on the perfect transfer theory of single qubit information in spin chain, the influence of two kinds of low-intensity magnetic fields independent on time acting on N=3 spin chain on single qubit quantum information perfect transfer is investigated. The Hamiltonian including magnetic field system is diagonalized, and the evolution operator effect is taken into account. Results show that a constant low-intensity magnetic field with uniform space and independent on time has no influence on fidelity of information transmission. The low-intensity magnetic field independent on time which is symmetry to the center of the spin chain and contrary in direction affects conditions for perfect transfer of quantum information. The stronger the magnetic field is, the shorter the time needed will be to realize perfect transfer.