Localization and quantum Hall effect in a two-dimensional periodic potential
Localization and quantum Hall effect in a two-dimensional periodic potential
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二维周期性势中的局域化和量子霍尔效应
DOI：
10.1088/0953-8984/6/39/015
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Yong
中科院分区：
文献类型：
--
作者：
Yong
在周期势和随机势的作用下，对二维最低朗道能级电子进行了数值研究。计算了无序变化时的霍尔电导、态密度和载流态密度。结果表明，随着无序的引入，携带量子化霍尔电导t(例如t>；1，类似的t<；-1)的子带中的态分别分裂为两个载流子单位电导和t-1。当无序度增加，带隙消失时，携带单位霍尔电流的态将与相邻子带中的载流态合并并湮灭，相隔一个小间隙。在此基础上，提出了载流态反无序的图示。对局域化长度也进行了计算，发现在一定条件下，延伸态在奇异能级出现。此外，对于1/3填充的朗道带，可以测量到的是霍尔电导的平台，而不是快速振荡。对于具有随机位置能量的磁场中的紧束缚电子，也得到了类似的结果。
A numerical study has been made of two-dimensional electrons in the lowest Landau level in the presence of a periodic potential and a random potential. The Hall conductance, density of states and density of current-carrying states are calculated when disorder is varied. The results show that the states in a subband carrying quantized Hall conductance t (t>1 for example, and similarly t<-1) are split into two carrying unit conductance and t-1, respectively, as disorder is introduced. The states carrying unit Hall current will merge and annihilate with that carrying -1 in the neighbouring subband separated by a small gap when disorder is increased and the gap vanishes. Based on this, a diagram of current-carrying states against disorder has been proposed. There is also a calculation on the localization length, and it is found that extended states appear at singular energies under certain conditions. Furthermore, it has been shown that a plateau in the Hall conductance, rather than a rapid oscillation, can be measured as a function of magnetic field for one-third-filled Landau bands. Similar results have been obtained for tight-binding electrons in a magnetic field with random site energies.
影响因子：
8.6
作者：
ABRAHAMS, E;ANDERSON, PW;RAMAKRISHNAN, TV
通讯作者：
RAMAKRISHNAN, TV