Fidelity and quantum phase transitions
Abstract
It is shown that the fidelity, a basic notion of quantum information science, may be used to characterize quantum phase transitions, regardless of what type of internal order is present in quantum many-body states. If the fidelity of two given states vanishes, then there are two cases: (1) they are in the same phase if the distinguishability results from irrelevant local information; or (2) they are in different phases if the distinguishability results from relevant long-distance information. The different effects of irrelevant and relevant information are quantified, which allows us to identify unstable and stable fixed points (in the sense of renormalization group theory). A physical implication of our results is the occurrence of the orthogonality catastrophe near the transition points.
Cite
@article{arxiv.cond-mat/0701608,
title = {Fidelity and quantum phase transitions},
author = {Huan-Qiang Zhou and John Paul Barjaktarevic},
journal= {arXiv preprint arXiv:cond-mat/0701608},
year = {2007}
}
Comments
5 pages, 2 figures