2014/11/14 by Qihang Liu, Xiuwen Zhang, L. B. Abdalla +2 · 2 citations
Physics and Astronomy · #cond-mat.mtrl-sci #cond-mat.mes-hall
paper · pdf · doi:10.1021/nl5043769
published as Nano Letters 15, 1222 (2015) · 19 pages, 4 figures
arxiv created 2014/11/14 · arxiv updated 2015/02/18
Phosphorene is a novel two-dimensional material that can be isolated through mechanical exfoliation from layered black phosphorus, but unlike graphene and silicene, monolayer phosphorene has a large band gap. It was thus unsuspected to exhibit band inversion and the ensuing topological insulator behavior. It has recently attracted interest because of its proposed application as field effect transistors. Using first-principles calculations with applied perpendicular electric field F we predict a continuous transition from the normal insulator to a topological insulator and eventually to a metal as a function of F. The continuous tuning of topological behavior with electric field would lead to spin-separated, gapless edge states, i.e., quantum spins Hall effect. This finding opens the possibility of converting normal insulating materials into topological ones via electric field, and making a multi-functional field effect topological transistor that could manipulate simultaneously both spins and charge carrier.