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arXiv · 1412.7919

Interfacial Fermi Loops from Interfacial Symmetries

Ryuji Takahashi·Shuichi Murakami
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Abstract

We propose a concept of interfacial symmetries such as interfacial particle-hole symmetry and interfacial time-reversal symmetry, which appear in interfaces between two regions related to each other by particle-hole or time-reversal transformations. These symmetries result in novel dispersion of interface states. In particular for the interfacial particle-hole symmetry the gap closes along a loop ("Fermi loop") at the interface. We numerically demonstrate this for the Fu-Kane-Mele tight-binding model. We show that the Fermi loop originates from a sign change of a Pfaffian of a product between the Hamiltonian and a constant matrix.

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Ryuji Takahashi, Shuichi Murakami. 2014-12-26. Interfacial Fermi Loops from Interfacial Symmetries. https://doi.org/10.1103/physrevlett.113.256406

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