• 文献标题:   Control of Giant Topological Magnetic Moment and Valley Splitting in Trilayer Graphene
  • 文献类型:   Article
  • 作  者:   GE ZH, SLIZOVSKIY S, JOUCKEN F, QUEZADA EA, TANIGUCHI T, WATANABE K, FAL KO VI, VELASCO J
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007 EI 1079-7114
  • 通讯作者地址:  
  • 被引频次:   10
  • DOI:   10.1103/PhysRevLett.127.136402
  • 出版年:   2021

▎ 摘  要

Bloch states of electrons in honeycomb two-dimensional crystals with multivalley band structure and broken inversion symmetry have orbital magnetic moments of a topological nature. In crystals with two degenerate valleys, a perpendicular magnetic field lifts the valley degeneracy via a Zeeman effect due to these magnetic moments, leading to magnetoelectric effects which can be leveraged for creating valleytronic devices. In this work, we demonstrate that trilayer graphene with Bernal stacking (ABA TLG), hosts topological magnetic moments with a large and widely tunable valley g factor (g(v)), reaching a value g(v )similar to 1050 at the extreme of the studied parametric range. The reported experiment consists in sublattice-resolved scanning tunneling spectroscopy under perpendicular electric and magnetic fields that control the TLG bands. The tunneling spectra agree very well with the results of theoretical modeling that includes the full details of the TLG tight-binding model and accounts for a quantum-dot-like potential profile formed electrostatically under the scanning tunneling microscope tip.