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Stability of the bulk gap for frustration-free topologically ordered quantum lattice systems

Mathematical Physics 2023-03-10 v3 Strongly Correlated Electrons math.MP Quantum Physics

Abstract

We prove that uniformly small short-range perturbations do not close the bulk gap above the ground state of frustration-free quantum spin systems that satisfy a standard local topological quantum order condition. In contrast with earlier results, we do not require a positive lower bound for finite-system Hamiltonians uniform in the system size. To obtain this result, we adapt the Bravyi-Hastings-Michalakis strategy to the GNS representation of the infinite-system ground state.

Keywords

Cite

@article{arxiv.2102.07209,
  title  = {Stability of the bulk gap for frustration-free topologically ordered quantum lattice systems},
  author = {Bruno Nachtergaele and Robert Sims and Amanda Young},
  journal= {arXiv preprint arXiv:2102.07209},
  year   = {2023}
}

Comments

Added Section 3.4 with an additional result; streamlined the exposition; updated references