Generalized Lieb-Schultz-Mattis Theorems for SPT Phases

by Tommy on 16/05/2017

I feel a major generalization ‘coming on.

https://arxiv.org/abs/1705.04691

Lieb-Schultz-Mattis theorems for symmetry protected topological phases, Yuan-Ming Lu, AMS 1127-81-159 (12 May 2017)

The Lieb-Schultz-Mattis (LSM) theorem and its descendants represent a class of powerful no-go theorems that rule out any short-range-entangled (SRE) symmetric ground state irrespective of the specific Hamiltonian, based only on certain microscopic inputs such as symmetries and particle filling numbers. In this work, we introduce and prove a new class of LSM-type theorems, where any symmetry-allowed SRE ground state must be a symmetry-protected topological (SPT) phase with robust gapless edge states. The key ingredient is to replace the lattice translation symmetry in usual LSM theorems by magnetic translation symmetry. These theorems provide new insights into numerical models and experimental realizations of SPT phases in interacting bosons and fermions.

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