• 文献标题:   Strange metal behavior of the Hall angle in twisted bilayer graphene
  • 文献类型:   Article
  • 作  者:   LYU R, TUCHFELD Z, VERMA N, TIAN HD, WATANABE K, TANIGUCHI T, LAU CN, RANDERIA M, BOCKRATH M
  • 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:  
  • 被引频次:   3
  • DOI:   10.1103/PhysRevB.103.245424
  • 出版年:   2021

▎ 摘  要

Twisted bilayer graphene (TBG) with interlayer twist angles near the magic angle approximate to 1.08 degrees hosts flat bands and exhibits correlated states including Mott-like insulators, superconductivity, and magnetism. A linear-intemperature normal state resistivity in TBG has been attributed to an exotic Planckian dissipation mechanism but can be equally well explained in terms of conventional electron-phonon scattering. To address this issue, we perform combined temperature-dependent transport measurements of both the longitudinal and Hall resistivities in near-magic-angle TBG. While the observed longitudinal resistivity follows linear temperature T dependence consistent with previous reports, the Hall resistance shows an anomalous T dependence with the cotangent of the Hall angle cot Theta(H) proportional to T-2. Boltzmann theory for quasiparticle transport predicts that both the resistivity and cot Theta(H) should have the same T dependence, contradicting the observed behavior. This failure of quasiparticle-based theories is reminiscent of other correlated strange metals such as cuprates.