• 文献标题:   Optical conductivity of single-layer graphene induced by temporal mass-gap fluctuations
  • 文献类型:   Article
  • 作  者:   BERNAD JZ
  • 作者关键词:   graphene, temporal massgap fluctuation, quantumstochastic time evolution, generalized kubo formula, optical conductivity
  • 出版物名称:   PHYSICA BCONDENSED MATTER
  • ISSN:   0921-4526
  • 通讯作者地址:   Tech Univ Darmstadt
  • 被引频次:   1
  • DOI:   10.1016/j.physb.2012.07.040
  • 出版年:   2012

▎ 摘  要

We consider the dynamics of charge carriers in single-layer graphene that are subject to random temporal fluctuations of their mass gap. The optical conductivity is calculated by incorporating the quantum-stochastic time evolution into the standard linear-response (Kubo) theory. We find that, for an intermediate range of frequencies below the average gap size, electron transport is enhanced by fluctuations. At the same time, in the limit of high as well as low frequencies, the conductivity is suppressed as the variance of gap fluctuations increases. In particular, the dc conductivity is always suppressed by a random temporal mass with nonvanishing mean value and vanishes in the zero-temperature limit. Our results are complementary to those obtained recently for static random-gap disorder in finite-size systems. (C) 2012 Elsevier B.V. All rights reserved.