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arXiv · 1407.4008

Proximity induced topological state in graphene

Igor Popov·Mauro Mantega·Awadhesh Narayan·Stefano Sanvito
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Abstract

The appearance of topologically protected states at the surface of an ordinary insulator is a rare occurrence and to date only a handful of materials are known for having this property. An intriguing question concerns the possibility of forming topologically protected interfaces between different materials. Here we propose that a topological phase can be transferred to graphene by proximity with the three-dimensional topological insulator Bi$_2$Se$_3$. By using density functional and transport theory we prove that, at the verge of the chemical bond formation, a hybrid state forms at the graphene/Bi$_2$Se$_3$ interface. The state has Dirac-cone-like dispersion at the $\Gamma$ point and a well-defined helical spin-texture, indicating its topologically protected nature. This demonstrates that proximity can transfer the topological phase from Bi$_2$Se$_3$ to graphene.

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Igor Popov, Mauro Mantega, Awadhesh Narayan, Stefano Sanvito. 2014-07-15. Proximity induced topological state in graphene. https://doi.org/10.1103/physrevb.90.035418

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