arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1604.03486cond-mat.stat-mechquant-ph
收藏

横向伊辛模型的量子关联集团平均场论

Quantum correlated cluster mean-field theory applied to the transverse Ising model

F. M. Zimmer, M. Schmidt, Jonas Maziero

摘要:

平均场论(MFT)是研究多体系统的主要分析计算工具之一。最近,有兴趣改进这种方法,主要是为了将这些系统的几何和相关属性。关联集团MFT(CCMFT)是一种改进,成功地做到了经典自旋系统。然而,即使是CCMFT在应用于量子系统时也存在一些缺陷。在这篇文章中,我们解决这个问题,提出了量子CCMFT(QCCMFT),它,在其自洽的平均场方程中使用一般的量子态,而不是以前的方法。我们将QCCMFT应用于蜂窝晶格、正方晶格和简单立方晶格中的横向伊辛模型,得到了较好的热相变居里温度和量子相变临界场的结果.事实上,我们的结果与通过精确解、级数展开或蒙特卡罗模拟获得的结果相匹配。

英文摘要:

Mean-field theory (MFT) is one of the main available tools for analytical calculations entailed in investigations regarding many-body systems. Recently, there have been an urge of interest in ameliorating this kind of method, mainly with the aim of incorporating geometric and correlation properties of these systems. The correlated cluster MFT (CCMFT) is an improvement that succeeded quite well in doing that for classical spin systems. Nevertheless, even the CCMFT presents some deficiencies when applied to quantum systems. In this article, we address this issue by proposing the quantum CCMFT (QCCMFT), which, in contrast to its former approach, uses general quantum states in its self-consistent mean-field equations. We apply the introduced QCCMFT to the transverse Ising model in honeycomb, square, and simple cubic lattices and obtain fairly good results both for the Curie temperature of thermal phase transition and for the critical field of quantum phase transition. Actually, our results match those obtained via exact solutions, series expansions or Monte Carlo simulations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑