Prefer a chat interface with context about you and your work?
Second-order topological insulator in van der Waals heterostructures of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>CoBr</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mrow><mml:mi>Pt</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mi>HgSe</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mrow><mml:mi>CoBr</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:math>
The second-order topological insulator, which has $(d\ensuremath{-}2)$-dimensional topological hinge or corner states, has been observed in three-dimensional materials, but has yet not been observed in a two-dimensional system. In this work we theoretically propose the realization of a second-order topological insulator in the van der Waals heterostructure of ${\mathrm{CoBr}}_{2}/{\mathrm{Pt}}_{2}{\mathrm{HgSe}}_{3}/{\mathrm{CoBr}}_{2}$. ${\mathrm{Pt}}_{2}{\mathrm{HgSe}}_{3}$ …