Symmetry constraints on many-body localization

@article{Potter2016SymmetryCO,
  title={Symmetry constraints on many-body localization},
  author={Andrew C. Potter and Romain Vasseur},
  journal={Physical Review B},
  year={2016},
  volume={94},
  pages={224206}
}
We derive general constraints on the existence of many-body localized (MBL) phases in the presence of global symmetries, and show that MBL is not possible with symmetry groups that protect multiplets (e.g. all non-Abelian symmetry groups). Based on simple representation theoretic considerations, we derive general Mermin-Wagner-type principles governing the possible alternative fates of non-equilibrium dynamics in isolated, strongly disordered quantum systems. Our results rule out the existence… 

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