Perfect transfer of the two-qubit quantum information in spin chain without any magnetic field is investigated. In our work, the spin chain is placed in a particular low-intensity magnetic field whose value is symmetrical about the chain and whose difference value between the nearest lattice points is constant. And the influence of the magnetic field has been studied by the method of matrix diagonalization. It is shown that the difference value of the magnetic field determines the fidelity of the two-qubit quantum information transfer in the spin chain. On the basis of this, we propose a theoretical scheme to achieve the quantum control of the two-qubit quantum information perfect transfer by applying this magnetic field, so that the perfect transfer time of information can be controlled arbitrarily as needed.

研究了自旋链中两量子位量子信息在没有任何磁场的情况下的完美传递。在我们的工作中，自旋链放置在特定的低强度磁场中，该磁场的值关于链对称，并且最近的晶格点之间的差值恒定。并通过矩阵对角化的方法研究了磁场的影响。结果表明，磁场的差值决定了自旋链中两量子位量子信息传递的保真度。在此基础上，我们提出了一种理论方案，通过施加磁场来实现两量子位量子信息的完美传递的量子控制，从而可以根据需要任意控制信息的完美传递时间。