Long-range quantum discord in critical spin systems
Quantum Physics
2012-04-11 v2 Statistical Mechanics
Abstract
We show that quantum correlations as quantified by quantum discord can characterize quantum phase transitions by exhibiting nontrivial long-range decay as a function of distance in spin systems. This is rather different from the behavior of pairwise entanglement, which is typically short-ranged even in critical systems. In particular, we find a clear change in the decay rate of quantum discord as the system crosses a quantum critical point. We illustrate this phenomenon for first-order, second-order, and infinite-order quantum phase transitions, indicating that pairwise quantum discord is an appealing quantum correlation function for condensed matter systems.
Cite
@article{arxiv.1012.5926,
title = {Long-range quantum discord in critical spin systems},
author = {J. Maziero and L. C. Céleri and R. M. Serra and M. S. Sarandy},
journal= {arXiv preprint arXiv:1012.5926},
year = {2012}
}