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arXiv · 1012.5926

Long-range quantum discord in critical spin systems

J. Maziero·L. C. Céleri·R. M. Serra·M. S. Sarandy
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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.

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J. Maziero, L. C. Céleri, R. M. Serra, M. S. Sarandy. 2010-12-29. Long-range quantum discord in critical spin systems. https://doi.org/10.1016/j.physleta.2012.03.029

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