Solving degenerate 2D frustration-free spin systems in sub-exponential time
Quantum Physics
2023-06-14 v2
Abstract
We give an improved analysis of approximate ground space projectors (AGSPs) to obtain a sharp error reduction bound in the setting a degenerate ground space. The improved tools imply that the recently proven 2D area law directly extends to sub-exponentially degenerate ground spaces and also yields a sub-exponential-time classical algorithm to compute the ground states. This time complexity cannot be improved beyond sub-exponential, even for the special case of classical unfrustrated systems in 2D.
Cite
@article{arxiv.2004.02850,
title = {Solving degenerate 2D frustration-free spin systems in sub-exponential time},
author = {Nilin Abrahamsen},
journal= {arXiv preprint arXiv:2004.02850},
year = {2023}
}
Comments
Revised to prepare for submission. Revised version includes arXiv:2003.08406