• 文献标题:   Unusual renormalization group (RG) flow and temperature-dependent phase transition in strongly-insulating monolayer epitaxial graphene
  • 文献类型:   Article
  • 作  者:   HUANG LI, YANG YF, LIU CW, ELMQUIST RE, LO ST, LIU FH, LIANG CT
  • 作者关键词:  
  • 出版物名称:   RSC ADVANCES
  • ISSN:   2046-2069
  • 通讯作者地址:   Natl Taiwan Univ
  • 被引频次:   1
  • DOI:   10.1039/c7ra05463g
  • 出版年:   2017

▎ 摘  要

By changing the measurement temperature (T), one can vary the effective sample size so as to study the renormalization group (RG) (or T-driven) flow of a semiconductor, a topological insulator, or a graphene device in the complex conductivity plane. Here we report RG flow of large-area, strongly disordered monolayer graphene epitaxially grown on SiC, which becomes insulating as T decreases for zero magnetic field. We observe cusp-like RG flow towards (sigma(xy) = e(2)/h, sigma(xx) = e(2)/h) where sigma(xy) and sigma(xx) are Hall conductivity and diagonal conductivity respectively. Such features, indicative of a fixed-temperature phase transition, have never been observed before and cannot be explained by existing RG models based on a modular symmetry group. Therefore, our results suggest the need for new theoretical models and experimental study leading to an understanding of strongly disordered two-dimensional materials such as graphene, few-layer black phosphorus, WSe2, and so on.