Gate-tunable quantum anomalous Hall effects in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>MnBi</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mi>Te</mml:mi></mml:mrow><mml:mn>4</mml:mn></mml:msub></mml:math> thin films
Chao Lei, A. H. MacDonald
Abstract
The quantum anomalous Hall (QAH) effect has recently been realized in thin films of intrinsic magnetic topological insulators (IMTIs) like $\mathrm{Mn}{\mathrm{Bi}}_{2}{\mathrm{Te}}_{4}$. Here we point out that the QAH gaps of these IMTIs can be optimized and that both axion insulator/semimetal and Chern insulator/semimetal transitions can be driven by electrical gate fields on the $\ensuremath{\sim}10$ meV/nm scale. This effect is described by combining a simplified coupled-Dirac-cone model of multilayer thin films with Schr\"odinger-Poisson self-consistent-field equations.
Topics & Concepts
Quantum anomalous Hall effectCondensed matter physicsMaterials scienceThin filmQuantum Hall effectTopological insulatorHall effectAxionQuantumMagnetic fieldPoint (geometry)Band gapQuantum spin Hall effectWeak localizationElectrical resistivity and conductivityOptoelectronicsTopological Materials and PhenomenaQuantum and electron transport phenomenaChemical and Physical Properties of Materials