Anomalous magneto-transport properties of bilayer phosphorene

TL;DR

This paper explores the complex magneto-transport behaviors of bilayer phosphorene under combined magnetic and electric fields, revealing unique Landau level structures and quantum Hall effects with potential experimental verification.

Contribution

It introduces a detailed theoretical analysis of bilayer phosphorene's Landau levels and quantum Hall phenomena under combined fields, highlighting novel anomalous transport properties.

Findings

Distinct Landau level subgroups with unique features

Complex quantum Hall conductivity structures including staircase and composite forms

Oscillatory phase diagrams showing crossover from integer to half-integer QH effect

Abstract

The magneto-transport properties of phosphorene are investigated by employing the generalized tight-binding model to calculate the energy bands. For bilayer phosphorene, a composite magnetic and electric field is shown to induce a feature-rich Landau level (LL) spectrum which includes two subgroups of low-lying LLs. The two subgroups possess distinct features in level spacings, quantum numbers, as well as field dependencies. These together lead to anomalous quantum Hall (QH) conductivities which include a well-shape, staircase and composite quantum structures with steps having varying heights and widths. The Fermi energy-magnetic field-Hall conductivity ($E_{F}-B_{z}-\sigma_{xy}$) and Fermi energy-electric field-Hall conductivity ($E_{F}-E_{z}-\sigma_{xy}$) phase diagrams clearly exhibit oscillatory behaviors and cross-over from integer to half-integer QH effect. The predicted results should be verifiable by magneto-transport measurements in a dual-gated system.