Quantum Discord in the Ground State of Spin Chains
Quantum Discord in the Ground State of Spin Chains
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DOI：
10.1142/s0217979213450306
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发表时间：
2012-08
影响因子：
1.7
通讯作者：
M. S. Sarandy;T. R. Oliveira;L. Amico
中科院分区：
文献类型：
--
作者：
M. S. Sarandy;T. R. Oliveira;L. Amico
The ground state of a quantum spin chain is a natural playground for investigating correlations. Nevertheless, not all correlations are genuinely of quantum nature. Here we review the recent progress to quantify the "quantumness" of the correlations throughout the phase diagram of quantum spin systems. Focusing to one spatial dimension, we discuss the behavior of quantum discord (QD) close to quantum phase transitions (QPT). In contrast to the two-spin entanglement, pairwise discord is effectively long-ranged in critical regimes. Besides the features of QPT, QD is especially feasible to explore the factorization phenomenon, giving rise to nontrivial ground classical states in quantum systems. The effects of spontaneous symmetry breaking are also discussed as well as the identification of quantum critical points through correlation witnesses.
