Efficient scheme for numerical simulations of the spin-bath decoherence
Efficient scheme for numerical simulations of the spin-bath decoherence
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DOI：
10.1103/physreve.67.056702
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发表时间：
2003-05-01
影响因子：
2.4
通讯作者：
De Raedt, HA
中科院分区：
文献类型：
--
作者：
Dobrovitski, VV;De Raedt, HA
我们证明了切比雪夫展开方法是研究量子系统自旋浴退相干的一个非常有效的数值工具。考虑了在研究由几个耦合自旋组成的量子系统的退相干时出现的两个典型问题：（i）确定系统的指针态和（ii）确定量子振荡的时间衰减。正如我们的研究结果表明，对于确定指针状态，基于切比雪夫的计划是至少一个因素的8比现有的算法的基础上的铃木-特罗特分解。对于第二类问题，基于Chebyshev的方法比基于Suzuki-Trotter的方法快3-4倍。这一结论定性地适用于具有不同自旋浴和不同哈密顿量的广泛系统。
We demonstrate that the Chebyshev expansion method is a very efficient numerical tool for studying spin-bath decoherence of quantum systems. We consider two typical problems arising in studying decoherence of quantum systems consisting of a few coupled spins: (i) determining the pointer states of the system and (ii) determining the temporal decay of quantum oscillations. As our results demonstrate, for determining the pointer states, the Chebyshev-based scheme is at least a factor of 8 faster than existing algorithms based on the Suzuki-Trotter decomposition. For problems of the second type, the Chebyshev-based approach is 3-4 times faster than the Suzuki-Trotter-based schemes. This conclusion holds qualitatively for a wide spectrum of systems, with different spin baths and different Hamiltonians.