• 文献标题:   Zero-field and time-reserval-symmetry-broken topological phase transitions in graphene
  • 文献类型:   Article
  • 作  者:   GUASSI MR, DINIZ GS, SANDLER N, QU FY
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Univ Brasilia
  • 被引频次:   9
  • DOI:   10.1103/PhysRevB.92.075426
  • 出版年:   2015

▎ 摘  要

We propose a quantum electronic device based on a strained graphene nanoribbon. Mechanical strain, internal exchange field, and spin-orbit couplings (SOCs) have been exploited as principle parameters to tune physical properties of the device. We predict a remarkable zero-field topological quantum phase transition between the time-reversal-symmetry-broken quantum spin Hall (QSH) and quantum anomalous Hall states, which was previously thought to take place only in the presence of finite magnetic field. We illustrate as intrinsic SOC is tuned, how two different helicity edge states located in the opposite edges of the nanoribbon exchange their locations. Our results indicate that the pseudomagnetic field induced by the strain could be coupled to the spin degrees of freedom through the SOC responsible for the stability of a QSH state. The controllability of this zero-field phase transition with strength and direction of the strain is also demonstrated. Our prediction offers a tempting prospect of strain, electric, and magnetic manipulation of the QSH effect.