Valley- and spin-dependent quantum Hall states in bilayer silicene

Abstract

The Hall conductivity ${\sigma }_{xy}$ of many condensed matter systems presents a step structure when a uniform perpendicular magnetic field is applied. We report the quantum Hall effect in buckled AB-bottom-top bilayer silicene and its robust dependence on the electronic valley and spin-orbit coupling. With the unique multi-valley electronic structure and the lack of spin degeneracy, the quantization of the Hall conductivity in this system is unlike the conventional sequence as reported for graphene. Furthermore, the conductivity plateaux take different step values for conduction ($2e^2/h$) and valence ($6e^2/h$) bands since their originating valleys present inequivalent degeneracy. We also report the emergence of fractions under significant effect of a uniform external electric field on the quantum Hall step structure by the separation of orbital distributions and the mixing of Landau levels from distinct valleys. The valley- and spin-dependent quantum Hall conductivity arises from the interplay of lattice geometry, atomic interaction, spin-orbit coupling, and external magnetic and electric fields.

References in corpus (10)

• Two-Dimensional Gas of Massless Dirac Fermions in Graphene
• Two and one-dimensional honeycomb structures of silicon and germanium
• Unconventional Integer Quantum Hall effect in graphene
• Evidence of silicene in honeycomb structures of silicon on Ag(111)
• The Non-Commutative Geometry of the Quantum Hall Effect
• The experimental observation of quantum Hall effect of l = 3 chiral charge carriers in trilayer graphene
• d+id' Chiral Superconductivity in Bilayer Silicene
• Landau levels and magneto-transport property of monolayer phosphorene
• Diverse Magnetic Quantization in Bilayer Silicene
• Integer Quantum Hall Effect in a Lattice Model Revisited: Kubo Formalism

Cited by in corpus (4)

• Stacking-configuration-enriched essential properties in bilayer silicenes
• Modeling Interlayer Interactions and Phonon Thermal Transport in Silicene Bilayer
• Engineering plasmon modes and their loss in armchair graphene nanoribbons by selected edge-extended defects
• Zigzag nanoribbon of gated bilayer hexagonal crystals with spontaneous edge magnetism