Longitudinal conductivity of massless fermions with tilted Dirac cone in magnetic field
Longitudinal conductivity of massless fermions with tilted Dirac cone in magnetic field
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DOI：
10.1103/physrevb.91.195413
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发表时间：
2015-04
影响因子：
3.7
通讯作者：
I. Proskurin;M. Ogata;Y. Suzumura
中科院分区：
文献类型：
--
作者：
I. Proskurin;M. Ogata;Y. Suzumura
本文研究了磁场中具有倾斜狄拉克锥的二维相对论电子气的纵向电导率。结果表明，电导率在平行于和垂直于圆锥倾斜方向上表现不同。在高磁场的非零朗道水平在垂直于倾斜的方向上的电导率修改非平凡的，在平行的情况下。在零温度下，从高到低磁场的狄拉克点的电导率的交叉进行了数值研究。研究发现，倾斜产生的各向异性的电导率随磁场的变化，这是不同的各向异性来自费米速度。我们还讨论了在有限温度和有限磁场下的电导率，这可以直接与$\alpha$-（BEDT-TTF）$_2$I$_3$有机导体的实验进行比较。我们发现，倾斜并没有影响这么多的磁场依赖性的电导率除了前因子。我们讨论了最近的实验数据的解释，并提出了一些建议，以检测在未来的实验倾斜的效果。
We investigate a longitudinal conductivity of a two-dimensional relativistic electron gas with a tilted Dirac cone in magnetic field. It is demonstrated that the conductivity behaves differently in the directions parallel and perpendicular to the tilting of the cone. At high magnetic fields the conductivity at non-zero Landau levels in the direction perpendicular to the tilting modifies non-trivially, in contrast to the parallel case. At zero temperature the crossover of the conductivity at the Dirac point from high to low magnetic field is studied numerically. It is found that that the tilting produces anisotropy of the conductivity which changes with the magnetic field which is different from the anisotropy coming from the Fermi velocity. We also discuss the conductivity at finite temperatures and finite magnetic fields which can be directly compared with the experiments in $\alpha$-(BEDT-TTF)$_2$I$_3$ organic conductor. We find that the tilting does not affect so much the magnetic-filed dependence of the conductivity except for the prefactor. We discuss the interpretation of recent experimental data and make some proposals to detect the effect of the tilting in future experiments.