arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1111.6014cond-mat.mes-hall
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离散1D Anderson模型中的消相干诱导电导率:偶数阶广义李雅普诺夫指数的新方法

Decoherence-induced conductivity in the discrete 1D Anderson model: A novel approach to even-order generalized Lyapunov exponents

Matías Zilly, Orsolya Ujsághy, Marko Woelki, Dietrich E. Wolf

摘要:

最近提出的退相干对电子输运影响的统计模型表明,当应用于一维Anderson模型时,退相干驱动的量子相干局域化转变为欧姆行为。在这里,我们推导出电阻率在欧姆的情况下,并表明,发生的过渡到本地化的行为时,相干长度超过一个值,它只取决于二阶广义李雅普诺夫指数$ξ^{-1}$。我们确定了无限大系统的$ξ^{-1}$的精确值。同样地,可以计算所有更高偶数阶广义李雅普诺夫指数,如针对四阶所例示的。通过假设无量纲电导$T$为对数正态极限分布,给出了局域化长度(反标准李雅普诺夫指数)的近似值。这种近似在弱无序的极限下工作得很好,除了带边和带中心。

英文摘要:

A recently proposed statistical model for the effects of decoherence on electron transport manifests a decoherence-driven transition from quantum-coherent localized to ohmic behavior when applied to the one-dimensional Anderson model. Here we derive the resistivity in the ohmic case and show that the transition to localized behavior occurs when the coherence length surpasses a value which only depends on the second-order generalized Lyapunov exponent $ξ^{-1}$. We determine the exact value of $ξ^{-1}$ of an infinite system for arbitrary uncorrelated disorder and electron energy. Likewise all higher even-order generalized Lyapunov exponents can be calculated, as exemplified for fourth order. An approximation for the localization length (inverse standard Lyapunov exponent) is presented, by assuming a log-normal limiting distribution for the dimensionless conductance $T$. This approximation works well in the limit of weak disorder, with the exception of the band edges and the band center.

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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