Hall transport in granular metals
Hall transport in granular metals
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DOI：
10.1103/physrevb.77.045116
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发表时间：
2007-06
影响因子：
3.7
通讯作者：
M. Kharitonov;K. Efetov
中科院分区：
文献类型：
--
作者：
M. Kharitonov;K. Efetov
本文提出了大隧穿电导g_{T}\gg_（1$）下颗粒系统的霍尔效应理论。霍尔传输基本上是由晶粒内的电子动力学，这是我们发现使用久保公式和图解技术，可以描述由非零扩散模式内的晶粒。我们表明，在库仑相互作用的霍尔电阻率$\rho_{xy}$既不依赖于隧道电导，也不对晶粒内的无序，并给出了经典的公式$\rho_{xy}=H/（n^* ec）$，其中$n^*$不同于晶粒内的载流子密度$n$由一个数值系数确定的形状的颗粒和颗粒晶格的类型。进一步，我们通过计算一阶修正量研究了库仑相互作用的影响，发现：（1）在超过隧穿逃逸率的较宽温度范围内，霍尔电阻率和电导率都是对数修正量，这是局域的，在均匀无序金属中是不存在的;（ii）在$T\ll\Ga$处对$\sig_{xy}$的大尺度"Altshuler-Aronov“修正消失，与均匀无序金属理论一致。
We present a theory of Hall effect in granular systems at large tunneling conductance $g_{T}\gg 1$. Hall transport is essentially determined by the intragrain electron dynamics, which, as we find using the Kubo formula and diagrammatic technique, can be described by nonzero diffusion modes inside the grains. We show that in the absence of Coulomb interaction the Hall resistivity $\rho_{xy}$ depends neither on the tunneling conductance nor on the intragrain disorder and is given by the classical formula $\rho_{xy}=H/(n^* e c)$, where $n^*$ differs from the carrier density $n$ inside the grains by a numerical coefficient determined by the shape of the grains and type of granular lattice. Further, we study the effects of Coulomb interactions by calculating first-order in $1/g_T$ corrections and find that (i) in a wide range of temperatures $T \gtrsim \Ga$ exceeding the tunneling escape rate $\Ga$, the Hall resistivity $\rho_{xy}$ and conductivity $\sig_{xy}$ acquire logarithmic in $T$ corrections, which are of local origin and absent in homogeneously disordered metals; (ii) large-scale ``Altshuler-Aronov'' correction to $\sig_{xy}$, relevant at $T\ll\Ga$, vanishes in agreement with the theory of homogeneously disordered metals.