An elementary proof of 1D LSM theorems
arXiv:2002.11176
Abstract
The Lieb-Schultz-Mattis (LSM) theorem and its generalizations forbids the existence of a unique gapped ground state in the presence of certain lattice and internal symmetries and thus imposes powerful constraints on the low energy properties of quantum many-body systems. We provide an elementary proof of a class of generalized LSM theorems in 1D using matrix product state representations and the representation theory of groups.
13 pages, 12 figures. Note added in Sec VII about important previous work that was brought to my attention after the appearance of this draft on arXiv, which had explored key aspects of this work