Buckled Honeycomb Lattice Materials and Unconventional Magnetic Responses

Date

2015-09-24

ORCID

Journal Title

Journal ISSN

Volume Title

Publisher

Royal Society of Chemistry

item.page.doi

Abstract

We study the magnetic response of two-dimensional buckled honeycomb-lattice materials. The buckling breaks the sublattice symmetry, enhances the spin-orbit coupling, and allows the tuning of a topological quantum phase transition. As a result, there are two doubly degenerate spin-valley coupled massive Dirac bands, which exhibit an unconventional Hall plateau sequence under strong magnetic fields. We show how to externally control the splitting of anomalous zeroth Landau levels, the prominent Landau level crossing effects, and the polarizations of spin, valley, and sublattice degrees of freedom. In particular, we reveal that in a p-n junction, spin-resolved fractionally quantized conductance appears in a two-terminal measurement with a spin-polarized current propagating along the interface. In the zero- or low-field regime where the Landau quantization is not applicable, we provide a semiclassical description for the anomalous Hall transport. We comment briefly on the effects of electron-electron interactions and Zeeman couplings to electron spins and to atomic orbitals. Our predictions can be examined in the magneto-transport and/or magneto-optic experiments.

Description

Keywords

Degree of freedom, Electron-electron interactions, Honeycomb structures, Magnetism, Phase transformations (Statistical physics), Quantum chemistry, Quantum electronics, Semiconductors--Junctions, Landau quantization, Quantum phase transitions, Spin polarized currents, Spin-orbit interactions, Magnetic fields, Symmetry (Mathematics), Electrospinning

item.page.sponsorship

We would like to thank D. L. Deng, Cheng-Cheng Liu, Yugui Yao, J. Xiao, and Chuanwei Zhang for helpful discussions. S. A. Y. is supported by SUTD-SRG-EPD2013062. H. P. is supported by NSFC Grant No. 11174022. F. Z. is supported by UT Dallas research enhancement funds.

Rights

©2015 The Royal Society of Chemistry. This article may not be further made available or distributed.

Citation

Collections