Intrinsic quantum anomalous Hall phase induced by proximity in the van der Waals heterostructure germanene/<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Cr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Ge</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Te</mml:mi><mml:mn>6</mml:mn></mml:msub></mml:mrow></mml:math>
Runling Zou, Fangyang Zhan, Baobing Zheng, Xiaozhi Wu, Jing Fan, Rui Wang
Abstract
A van der Waals heterostructure combined with intrinsic magnetism and topological orders have recently paved attractive avenues to realize quantum anomalous Hall effects. In this work, using first-principles calculations and effective model analysis, we propose that the robust quantum anomalous Hall states with sizable band gaps emerge in the van der Waals heterostructure of germanene/${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$. This heterostructure possesses high thermodynamic stability, thus facilitating its experimental fabrication. Furthermore, we uncover that the proximity effect enhances the coupling between the germanene and ${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$ layers, inducing the nontrivial band gaps in a wide range from 29 to 72 meV. The chiral edge states inside the band gap, leading to Hall conductance quantized to $\ensuremath{-}{e}^{2}/h$, are clearly visible. These findings provide an ideal candidate to detect the quantum anomalous Hall states and realize further applications to nontrivial quantum transport at a high temperature.