arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1203.4599cond-mat.dis-nn
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量子$k$ -核渗流的能级统计

Level statistics for quantum $k$-core percolation

L. Cao, J. M. Schwarz

摘要:

量子$k$ -核逾渗是研究$k$ -核逾渗团簇的量子输运,其中每个被占据的键必须至少有$k$被占据的相邻键。随着键占据概率$p$从零增加到1,系统经历从绝缘相到金属相的转变。当无序的长度尺度$l_d$远大于相干长度$l_c$时,早期对贝特晶格上量子传导的分析计算表明,对于$k=3$,金属-绝缘体跃迁(MIT)是不连续的,这表明了一种新的普遍性的无序驱动的量子MIT。在这里,我们数值计算的水平间距分布的键占据概率$p$和系统的大小的函数上的贝特式晶格。能级间距分析表明,对于$k=0$,量子逾渗临界几率$p_q$大于几何逾渗临界几率$p_c$,且跃迁是连续的.相反,对于$k=3$,$p_q=p_c$和过渡是不连续的,使得这些数值结果与我们以前的工作是一致的,重申了一个新的普遍性类的无序驱动的量子MIT。

英文摘要:

Quantum $k$-core percolation is the study of quantum transport on $k$-core percolation clusters where each occupied bond must have at least $k$ occupied neighboring bonds. As the bond occupation probability, $p$, is increased from zero to unity, the system undergoes a transition from an insulating phase to a metallic phase. When the lengthscale for the disorder, $l_d$, is much greater than the coherence length, $l_c$, earlier analytical calculations of quantum conduction on the Bethe lattice demonstrate that for $k=3$ the metal-insulator transition (MIT) is discontinuous, suggesting a new universality class of disorder-driven quantum MITs. Here, we numerically compute the level spacing distribution as a function of bond occupation probability $p$ and system size on a Bethe-like lattice. The level spacing analysis suggests that for $k=0$, $p_q$, the quantum percolation critical probability, is greater than $p_c$, the geometrical percolation critical probability, and the transition is continuous. In contrast, for $k=3$, $p_q=p_c$ and the transition is discontinuous such that these numerical findings are consistent with our previous work to reiterate a new universality class of disorder-driven quantum MITs.

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。

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