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arXiv · 1906.11662

A generalized boundary condition applied to Lieb-Schultz-Mattis type ingappabilities and many-body Chern numbers

Yuan Yao·Masaki Oshikawa
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Abstract

We introduce a new boundary condition which renders the flux-insertion argument for the Lieb-Schultz-Mattis type theorems in two or higher dimensions free from the specific choice of system sizes. It also enables a formulation of the Lieb-Schultz-Mattis type theorems in arbitrary dimensions in terms of the anomaly in field theories of $1+1$ dimensions with a bulk correspondence as a BF-theory in 2+1 dimensions. Furthermore, we apply the anomaly-based formulation to the constraints on a half-filled spinless fermion on a square lattice with $π$ flux, utilizing time-reversal, the magnetic translation and on-site internal $U(N)$ symmetries. This demonstrates the role of time-reversal anomaly on the ingappabilities of a lattice model.

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Yuan Yao, Masaki Oshikawa. 2020-05-14. A generalized boundary condition applied to Lieb-Schultz-Mattis type ingappabilities and many-body Chern numbers. https://doi.org/10.1103/physrevx.10.031008

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