Stacking-dependent topological phase in bilayer <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>M</mml:mi><mml:mi mathvariant="normal">B</mml:mi><mml:msub><mml:mi mathvariant="normal">i</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi mathvariant="normal">T</mml:mi><mml:msub><mml:mi mathvariant="normal">e</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mi>M</mml:mi><mml:mo>=</mml:mo><mml:mi>Ge</mml:mi><mml:mo>,</mml:mo><mml:mi mathvariant="normal">Sn</mml:mi><mml:mo>,</mml:mo><mml:mi mathvariant="normal">Pb</mml:mi></mml:mrow><mml:mo>)</mml:mo></mml:math>
Rui Peng, Yandong Ma, Hao Wang, Baibiao Huang, Ying Dai
Abstract
Inspired by the breakthroughs of twisted bilayer graphene, stacking-dependent phenomena are recently emerging as fascinating objects of condensed matter research, harboring a variety of new physics. However, current studies are restricted to electronic, superconducting and magnetic properties. Here, using first-principles calculations, we reveal the connection between stacking order and topological property in bilayer $M\mathrm{B}{\mathrm{i}}_{2}\mathrm{T}{\mathrm{e}}_{4}(M=\mathrm{Ge},\mathrm{Sn},\mathrm{Pb})$. We show the stacking order determines the topological property. Upon changing the stacking order, one can achieve topological phase transition between trivial and nontrivial states. We unveil that this stacking-dependent topological property is attributed to the interlayer $\mathrm{Te}\ensuremath{-}{p}_{z}$ orbitals coupling, which is closely related to the stacking order. Our work not only expands the scope of stacking-dependent properties but also provides a promising experimental platform to study this novel stacking-dependent topological property.