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arXiv 0705.0622cond-mat.mes-hall
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具有随机磁通量的二维手征系统的临界电导

Critical conductance of two-dimensional chiral systems with random magnetic flux

P. Markos, L. Schweitzer

摘要:

数值研究了二维格点系统的零温输运性质,其中每个格点具有静态随机磁通量,平均值为零。我们研究了两端电导及其对能量、样品尺寸和磁通量强度的依赖关系。边界条件的影响和奇数的数量在横向上的网站也进行了研究。我们证实了在能带中间存在一个临界手征态,并计算了局域化长度发散的临界指数nu=0.35 +/-0.03。样本平均尺度无关的临界电导<g>_c原来是一个函数的通量波动的幅度,而相应的电导分布的方差似乎是普遍的。带中心以外的所有电子态被发现是本地化。

英文摘要:

The zero temperature transport properties of two-dimensional lattice systems with static random magnetic flux per plaquette and zero mean are investigated numerically. We study the two-terminal conductance and its dependence on energy, sample size, and magnetic flux strength. The influence of boundary conditions and of the oddness of the number of sites in the transverse direction is also studied. We confirm the existence of a critical chiral state in the middle of the energy band and calculate the critical exponent nu=0.35 +/- 0.03 for the divergence of the localization length. The sample averaged scale independent critical conductance <g>_c turns out to be a function of the amplitude of the flux fluctuations whereas the variance of the respective conductance distributions appears to be universal. All electronic states outside of the band center are found to be localized.

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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