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arXiv cond-mat/9803003cond-mat.mes-hall
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多层量子霍尔态表面的电导、电导涨落和能级统计

Conductances, Conductance Fluctuations, and Level Statistics on the Surface of Multilayer Quantum Hall States

Vasiliki Plerou, Ziqiang Wang

摘要:

研究了整数量子霍尔态下耦合多层异质结构二维表面的输运性质。我们强调了表面态的临界性和热力学极限下的相相干输运性质。本文详细讨论了一种新的、稳定的大规模电导计算的传输矩阵方法。然后将其应用于描述多层边缘态的量子力学隧穿和杂质散射的有向网络模型。我们计算了平行于外磁场方向的双探针电导,其波动和统计分布作为层间隧穿强度的函数。使用有限尺寸标度,系综平均电导和电导波动的渐近标度函数计算了固定的纵横比,并发现在显着的协议与使用超对称非线性$σ$模型方法得到的分析结果。的电导分布是确定在准一维金属,绝缘,以及交叉制度的比较,在单层量子霍尔过渡。我们提出,第一次,在转移矩阵的本征值谱的水平统计的详细研究。金属和绝缘统计的共存,观察到的交叉制度,这是由于出现了一个有限范围的水平排斥的交叉制度,分离的金属(Wigner-surprise)行为在小的水平间距从绝缘(不相关或泊松)行为在大的水平间距。

英文摘要:

The transport properties on the two-dimensional surface of coupled multilayer heterostructures are studied in the integer quantum Hall states. We emphasize the criticality of the surface state and the phase coherent transport properties in the thermodynamic limit. A new, stable numerical algorithm for large scale conductance calculations in the transfer matrix approach is discussed in detail. It is then applied to a directed network model describing the quantum mechanical tunneling and impurity scattering of the multilayer edge states. We calculate the two-probe conductance in the direction parallel to the external magnetic field, its fluctuations and statistical distributions as a function of the interlayer tunneling strength. Using finite size scaling, the asymptotic scaling functions of the ensemble averaged conductance and the conductance fluctuations are calculated for a fixed aspect ratio and found to be in remarkable agreement with the analytical results obtained using the supersymmetric nonlinear $σ$-model approach. The conductance distribution is determined in the quasi-one-dimensional metallic, insulating, as well as the crossover regime where comparisons are made to that at the single-layer quantum Hall transition. We present, for the first time, a detailed study of the level statistics in the eigenvalue spectrum of the transfer matrix. Coexistence of metallic and insulating statistics is observed in the crossover regime, which is attributed to the emergence of a finite range level repulsion in the crossover regime, separating the metallic (Wigner-surmise) behavior at small level spacings from the insulating (uncorrelated or Poisson) behavior at large level spacings.

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