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arXiv · 1908.08958

A 1d lattice model for the boundary of the quantum spin-Hall insulator

Max A. Metlitski
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Abstract

We present a 1d lattice model that mimics the boundary of the conventional 2d quantum spin-Hall insulator (QSHI) with $U(1)$ symmetry and time-reversal $T$, satisfying $T^2 = (-1)^F$. Our construction utilizes a local tensor product Hilbert space of finite site dimension with a non-onsite symmetry action. We discuss how several signature properties of the QSHI, such as the fractional charge on $T$-domain walls and Kramers parity switching upon $π$-flux threading, are manifested in our treatment. We also present a 1d Hamiltonian whose ground state realizes the conventional Luttinger-liquid phase of the QSHI edge.

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Max A. Metlitski. 2019-08-23. A 1d lattice model for the boundary of the quantum spin-Hall insulator. https://arxiv.org/abs/1908.08958

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