论文标题
金属层对可变范围跳跃的二极化效应
The polaronic effect of a metal layer on variable range hopping
论文作者
论文摘要
我们研究了金属板对二维电子玻璃（EG）系统可变范围跳跃（VRH）电导率的影响。已知VRH电导率对温度具有拉伸的指数依赖性，指数$ p $取决于EG的单个状态颗粒密度的形状（DOS）。对于常数DOS $ P = 1/3 $，对于线性DOS $ P = 1/2 $，也称为Mott's和Efros-Shklovskii的VRH。板的存在会对EG系统（静态和动态）产生两种影响。众所周知的静态效应解释了EG中库仑排斥的额外筛选以及DOS中库仑间隙的部分填充。反过来，这在非常低的温度下导致电导率增加。在这里，我们研究了与二极化现象有关的互补动力学效应。我们的主要结果是对标准声子辅助跳跃的动态抑制，因此，与低温静态效应相比，在温度范围更大的电导率中抑制了电导率。讨论了与实验的关系。
We investigate the effect of a metal plate on the variable range hopping (VRH) conductivity of a two dimensional electron-glass (EG) system. The VRH conductivity is known to have a stretched exponential dependence on temperature, with an exponent $p$ that depends on the shape of the EG's single particle density of states (DOS). For constant DOS $p=1/3$ and for linear DOS $p=1/2$, also known as Mott's and Efros-Shklovskii's VRH respectively. The presence of the plate causes two effects on the EG system, static and dynamic. The well known static effect accounts for the additional screening of the Coulomb repulsion in the EG and for the partial filling of the Coulomb gap in the DOS. This in turn causes an increase of the conductivity at very low temperatures. Here we investigate the complementary dynamical effect, which is related to the polaronic phenomena. Our main result is the dynamical suppression of the standard phonon assisted hopping and, thus, suppression of the conductivity in a much wider range of temperatures as compared to the low temperature static effect. The relation to experiments is discussed.
