石墨烯量子磁输运性质的电场调控

发布时间：2018-06-24 16:24

本文选题：石墨烯 + 带宽　；参考：《太原理工大学》2017年硕士论文

【摘要】：石墨烯(Graphene)是材料科学和凝聚态物理领域迅速崛起的明星。作为低维电子系统的石墨烯材料一经被制备出来就展示了反常的电学性质,例如:反常的量子霍尔效应;石墨烯在一维周期性电学或磁学调制势下,其扩散电导率会出现Weiss振荡。这些新奇的物理效应都与石墨烯上载流子所具有的相对论特性有关。在理论上,石墨烯在面外加垂直磁场和一维周期性电学或磁学调制势下,其扩散电导率会出现Weiss振荡已经有所研究。我们进一步分别探索了面外加垂直磁场和面内加横向电场以及一维周期性弱调制磁学势的多场耦合作用和面外加垂直磁场和面内加横向电场以及一维周期性弱调制电学势的多场耦合作用下,石墨烯的量子磁输运性质及其相关的一些物理效应。本文主要结论如下:1.面外加垂直磁场、面内加横向电场以及一维周期性弱调制电学势下石墨烯中的的带宽和态密度出现了异常振荡。2.面外加垂直磁场、面内加横向电场以及一维周期性弱调制磁学势的多场耦合作用和面外加垂直磁场、面内加横向电场以及一维周期性电学势的多场耦合作用下,磁致电导率在静电场存在下,会呈现Weiss振荡,且Weiss振荡的振幅和电导率数值都随着静电场的增加而增加。有趣的是,当电场与磁场的比值达到某一临界值,即β_1=E/(v_FB)=1时,Weiss振荡会突然消失。
[Abstract]:Graphene is a rapidly rising star in material science and condensed matter physics. Graphene materials, which are prepared as low-dimensional electronic systems, exhibit anomalous electrical properties, such as the anomalous quantum Hall effect, graphene under one-dimensional periodic electrical or magnetic modulation potential, The diffusion conductivity will appear Weiss oscillation. These novel physical effects are related to the relativistic properties of carriers on graphene. Theoretically, Weiss oscillations of diffusion conductivity of graphene have been studied in the presence of vertical magnetic field and one-dimensional periodic electrical or magnetic modulation potential. We further explore the multi-field coupling of the surface applied vertical magnetic field and the in-plane transverse electric field and the one-dimensional periodic weakly modulated magnetic potential, the plane applied vertical magnetic field and the in-plane transverse electric field, and the one-dimensional periodic weak modulation respectively. In the multi-field coupling of electrical potential, Quantum magnetic transport properties of graphene and some related physical effects. The main conclusions of this paper are as follows: 1. The bandwidth and density of states in graphene show abnormal oscillations under the applied vertical magnetic field in the plane, the transverse electric field in the plane and the one-dimensional periodic weakly modulated electric potential. Under the coupling of the vertical magnetic field in the plane, the transverse electric field in the plane and the one-dimensional periodic weakly modulated magnetic potential in the plane, and the vertical magnetic field in the plane, the transverse electric field in the plane and the one-dimensional periodic electric potential in the plane are coupled in many fields. In the presence of electrostatic field, the magnetic conductivity exhibits Weiss oscillation, and the amplitude and conductivity of the Weiss oscillation increase with the increase of electrostatic field. Interestingly, the Weiss oscillation will suddenly disappear when the ratio of electric field to magnetic field reaches a certain critical value, that is, 尾 _ 1 / (v _ S _ FB) = 1.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O469

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