ORIGIN OF ANOMALOUS MAGNETIC BREAKDOWN FREQUENCIES IN QUASI-TWO-DIMENSIONAL ORGANIC CONDUCTORS
ORIGIN OF ANOMALOUS MAGNETIC BREAKDOWN FREQUENCIES IN QUASI-TWO-DIMENSIONAL ORGANIC CONDUCTORS
复制标题
准二维有机导体异常磁击穿频率的起源
DOI：
10.1103/physrevb.56.11566
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发表时间：
1997
影响因子：
3.7
通讯作者：
J. Brooks
中科院分区：
文献类型：
--
作者：
P. S. Sandhu;Ju H. Kim;J. Brooks
研究了准二维有机导体α−(B E D T−T T F)2 KHg(SCN)4和κ−(B E D T−T T F)2 Cu(NCS)2的De Haas van Alphen(DHvA)效应中反常磁击穿频率的来源。本模型自然地描述了共存的闭合和开费米面之间的磁击穿现象，并解释了实验观察到的半经典图像中被禁止的频率。我们发现，dHvA信号中这些反常频率的出现是一种量子力学效应，它是由于费米能级附近两个部分占据带中的态对场的依赖程度不同而引起的。
We investigate the origin of anomalous magnetic breakdown frequencies in the de Haas–van Alphen (dHvA) effect in quasi-two-dimensional organic conductors such as α−(B E D T− T T F) 2 KHg (SCN) 4 and κ−(B E D T− T T F) 2 Cu (NCS) 2. A tight-binding model based on their realistic band structure is constructed and solved numerically to compute the field dependence of the magnetization. The present model provides a natural description for the phenomenon of magnetic breakdown between coexisting closed and open Fermi surfaces and accounts for the experimentally observed frequencies that are forbidden in the semiclassical picture. We find that the appearance of these anomalous frequencies in the dHvA signal is a quantum-mechanical effect which arises from differences in field dependence of the states in the two partially occupied bands near the Fermi level.