• 文献标题:   Spin and orbital metallic magnetism in rhombohedral trilayer graphene
  • 文献类型:   Article
  • 作  者:   HUANG CL, WOLF TMR, QIN W, WEI NM, BLINOV IV, MACDONALD AH
  • 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:   0
  • DOI:   10.1103/PhysRevB.107.L121405
  • 出版年:   2023

▎ 摘  要

We provide a theoretical interpretation of the metallic broken spin-valley (flavor) symmetry states recently discovered in hole-doped rhombohedral trilayer (ABC) graphene in large electric displacement fields. Our con-clusions about the phase diagram and phase transitions combine insights from ABC graphene electronic structure models and mean-field theory, and are guided by the precise magneto-oscillation Fermi-surface-area measure-ments of recent experiments. We find that the principle of momentum-space condensation plays a key role in determining Fermi-surface reconstructions enabled by broken flavor symmetries when the single-particle bands imply thin annular Fermi seas. The reconstructed Fermi sea consists of one large outer Fermi-surface-enclosed majority-flavor states in reciprocal-space area Amaj and one or more small inner holelike Fermi-surface-enclosed minority-flavor states in Amin that are primarily responsible for nematic order. The competing ground states (valley-Ising, valley-XY, and spin-polarized state) have different Amaj/Amin and exchange energy maximizes this ratio and selects valley-XY nematic metal as the lowest-energy state. We discuss how the nematic pockets explain the observed fractionalization of quantum oscillation frequencies, and propose anisotropic transport and the nonlinear Hall effect as additional observables.