Quantum computing with antiferromagnetic spin clusters
Quantum computing with antiferromagnetic spin clusters
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DOI：
10.1103/physrevb.68.134417
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发表时间：
2003-10-01
影响因子：
3.7
通讯作者：
Loss, D
中科院分区：
文献类型：
--
作者：
Meier, F;Levy, J;Loss, D
我们发现，一个广泛的自旋团簇与反铁磁团簇内交换相互作用允许一个定义一个量子比特。对于这些自旋簇量子位，初始化、量子门操作和读出可以使用与单自旋相同的技术。自旋团簇量子位的量子门操作不需要控制团簇内交换相互作用。影响量子门所需的电场和磁场只需要在自旋簇的长度尺度上控制，而不是在单个自旋的尺度上控制。在这里，我们计算了将逻辑量子比特状态与下一个激发态分开的能隙以及决定量子门操作时间的矩阵元素。我们讨论了由s=1/2自旋的一维和二维阵列形成的自旋团簇量子比特以及由s>1/2自旋形成的团簇。我们说明了自旋团簇量子比特的各种建议的实现自旋量子比特的优势，并分析了自旋团簇大小的退相干时间的标度。
We show that a wide range of spin clusters with antiferromagnetic intracluster exchange interaction allows one to define a qubit. For these spin cluster qubits, initialization, quantum gate operation, and readout are possible using the same techniques as for single spins. Quantum gate operation for the spin cluster qubit does not require control over the intracluster exchange interaction. Electric and magnetic fields necessary to effect quantum gates need only be controlled on the length scale of the spin cluster rather than the scale for a single spin. Here, we calculate the energy gap separating the logical qubit states from the next excited state and the matrix elements which determine quantum gate operation times. We discuss spin cluster qubits formed by one- and two-dimensional arrays of s=1/2 spins as well as clusters formed by spins s>1/2. We illustrate the advantages of spin cluster qubits for various suggested implementations of spin qubits and analyze the scaling of decoherence time with spin cluster size.