Low‐temperature variational approximation for the Feynman quantum propagator and its application to the simulation of quantum systems
Low‐temperature variational approximation for the Feynman quantum propagator and its application to the simulation of quantum systems
复制标题
费曼量子传播器的低温变分逼近及其在量子系统模拟中的应用
DOI：
10.1063/1.458189
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
B. Berne
中科院分区：
文献类型：
--
作者：
Jianshu Cao;B. Berne
Mak和Andersen的低温传播子[J. Chem. Phys. 92，2953（1990）]允许量子系统的费曼路径积分计算机模拟更快地收敛。该传播器的有效性对有效频率的选择非常敏感，Mak和Andersen所做的选择虽然很好，但不是最佳的。本文利用谐波参考系和变分原理计算了这一有效频率。仿真结果表明，当这是在低温传播，结果收敛速度比其他选择的频率。此外，一个能量估计，这使得该有效的潜力，用于确定的量子系统的能量。此外，使用自由粒子参考系中的质心密度的累积展开，推导出有效势沿着以及相应的能量估计，并与上述进行比较。
The low‐temperature propagator of Mak and Andersen [J. Chem. Phys. 92, 2953 (1990)] allows for much more rapid convergence of Feynman path integral computer simulations of quantum systems. The effectiveness of this propagator is very sensitive to the choice of an effective frequency and the choice of this made by Mak and Andersen, although good, is not optimum. In this paper a harmonic reference system is used together with a variation principle to compute this effective frequency. Simulations show that when this is used in the low temperature propagator, the results converge much more rapidly than for other choices of the frequency. Moreover, an energy estimator is derived, which allows this effective potential to be used for the determination of the energy of the quantum system. In addition, using a cumulant expansion of the centroid density in the free particle reference system, an effective potential along with a corresponding energy estimator is derived and compared to the above.
影响因子：
4.4
作者：
MAKRI, N;MILLER, WH
通讯作者：
MILLER, WH