海森堡自旋链中纠缠的双向传输

Bidirectional transfer of entanglement in an open Heisenberg spin chain

提出了一种利用开放海森堡铁磁自旋链为信道双向传输量子纠缠的方案.通过对量子信道施加静态磁场,可以实现自旋链两端纠缠的周期性交换.经过一个交换周期的时间演化后,原本属于孤立量子比特和自旋链某一末端粒子之间的纠缠会转换成该量子比特和自旋链另一末端粒子之间的纠缠.分析了交换行为和自旋链长度、磁场、耦合强度、各向异性常数之间的关系,并讨论了由4个粒子构成的简单系统中类似的纠缠交换行为.

A scheme to bidirectionallv transfer quantum entanglement in an open Heisenberg ferromagnetic spin chain is proposed. The entanglement at the two ends of spin chains can be swapped periodically by applying static magnetic field to the information channel. After a swap period,the entanglement between an uncoupled qubi/and one end spin will be shared by the qubit and the other end spin. The relation between the swap action and chain length, magnetic field, couple strength, anisotropic constant is analyzed. And the similar swap phenomenon in the four-spin system is discussed analytically.