Orbital magnetic moments in insulating Dirac systems: Impact on magnetotransport in graphene van der Waals heterostructures
arXiv:1408.1200 · doi:10.1103/PhysRevB.90.205408
Abstract
In honeycomb Dirac systems with broken inversion symmetry, orbital magnetic moments coupled to the valley degree of freedom arise due to the topology of the band structure, leading to valley-selective optical dichroism. On the other hand, in Dirac systems with prominent spin-orbit coupling, similar orbital magnetic moments emerge as well. These moments are coupled to spin, but otherwise have the same functional form as the moments stemming from spatial inversion breaking. After reviewing the basic properties of these moments, which are relevant for a whole set of newly discovered materials, such as silicene and germanene, we study the particular impact that these moments have on graphene nanoengineered barriers with artificially enhanced spin-orbit coupling. We examine transmission properties of such barriers in the presence of a magnetic field. The orbital moments are found to manifest in transport characteristics through spin-dependent transmission and conductance, making them directly accessible in experiments. Moreover, the Zeeman-type effects appear without explicitly incorporating the Zeeman term in the models, i.e., by using minimal coupling and Peierls substitution in continuum and the tight-binding methods, respectively. We find that a quasiclassical view is able to explain all the observed phenomena.
References in corpus (14)
- The Valley Hall Effect in MoS2 Transistors
- Valley Dependent Optoelectronics from Inversion Symmetry Breaking
- Valley-Polarized Metals and Quantum Anomalous Hall Effect in Silicene
- Detecting Topological Currents in Graphene Superlattices
- Spin-Orbit Proximity Effect in Graphene
- Quantum conductance of graphene nanoribbons with edge defects
- Intrinsic spin Hall effect in monolayers of group-VI dichalcogenides: A first-principles study
- Pseudospin Magnetism in Graphene
- Quantum Anomalous Hall State in Bilayer Graphene
- Unconventional Quantum Hall Effect and Tunable Spin Hall Effect in MoS2 Trilayers
- Spin-Valley Optical Selection Rule and Strong Circular Dichroism in Silicene
- Lattice Theory of Pseudospin Ferromagnetism in Bilayer Graphene: Competing Orders and Interaction Induced Quantum Hall States
- Theory of Anomalous Quantum Hall Effects in Graphene
- Spin-valley filtering in strained graphene structures with artificially induced carrier mass and spin-orbit coupling