Irreducible many-body correlations in topologically ordered systems
Abstract
Topologically ordered systems exhibit large-scale correlation in their ground states, which may be characterized by quantities such as topological entanglement entropy. We propose that the concept of irreducible many-body correlation, the correlation that cannot be implied by all local correlations, may also be used as a signature of topological order. In a topologically ordered system, we demonstrate that for a part of the system with holes, the reduced density matrix exhibits irreducible many-body correlation which becomes reducible when the holes are removed. The appearance of these irreducible correlations then represents a key feature of topological phase. We analyze the many-body correlation structures in the ground state of the toric code model in an external magnetic field, and show that the topological phase transition is signaled by the irreducible many-body correlations.
Cite
@article{arxiv.1402.4245,
title = {Irreducible many-body correlations in topologically ordered systems},
author = {Yang Liu and Bei Zeng and D. L. Zhou},
journal= {arXiv preprint arXiv:1402.4245},
year = {2019}
}