自旋模型在实现量子信息处理中起着很重要的作用.将自旋之间的海森堡相互作用作为最基本量子比特之间的相互作用,将会使量子比特之间产生量子纠缠;同时忽略掉自旋之间相互作用的各向异性可直接用来实现(swap)n量子门,再配以单量子比特旋转门,可构成完备的量子计算基本门.事实上,各向异性相互作用是存在于任何固态材料中的,其对实现量子逻辑门的影响很值得研究.本文讨论了在非均匀外场下XYZ模型的双量子比特swap门的实现问题,给出非均匀外场以及各向异性相互作用导致的swap门操作的误差.
Spin model plays an important role in the realization of quantum information processing. Quantum entanglement can be constructed, also (swap)~n quantum log ic gate is available if anisotropy is ignored, when Heisenberg interaction between spins is used; thus a complete quantum computing gate will be realized by combining single-qubit rotation gate. To study the influence of anisotropy on logic gate has high academic value since anisotropy is inevitable in any solid material. In this paper, swap operation in a two-qubit anisotropy XYZ model in the presence of an inhomogeneous magnetic field is discussed. The swap errors caused by the anisotropy parameter ν of the exchange interaction between spins and the inhomogeneous field δ are evaluated. We can see clearly when the s wap operation can be approximately used as an ideal swap gate.