Quantum Correlations in Spin Chains at Finite Temperatures and Quantum Phase Transitions
Quantum Correlations in Spin Chains at Finite Temperatures and Quantum Phase Transitions
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DOI：
10.1103/physrevlett.105.095702
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发表时间：
2010-08-25
影响因子：
8.6
通讯作者：
Rigolin, Gustavo
中科院分区：
文献类型：
--
作者：
Werlang, T. G.;Trippe, C.;Rigolin, Gustavo
我们计算了有限温度下海森堡模型（XXZ哈密顿量）描述的无限链中最近邻量子位（自旋1/2）之间的量子相关[量子不和谐（QD）]和纠缠（EOF）。该链处于热力学极限，并在温度T（正则系综）时与热源热化。我们表明，与EOF和其他热力学量相比，QD即使在有限t下也能突出与该模型的量子相变（QPT）相关的临界点。当人们无法达到可以看到QPT的温度时，QD的这一显着性质可能对QPT的实验表征具有重要意义。
We compute the quantum correlation [quantum discord (QD)] and the entanglement (EOF) between nearest-neighbor qubits (spin-1/2) in an infinite chain described by the Heisenberg model (XXZ Hamiltonian) at finite temperatures. The chain is in the thermodynamic limit and thermalized with a reservoir at temperature T (canonical ensemble). We show that QD, in contrast to EOF and other thermodynamic quantities, spotlight the critical points associated with quantum phase transitions (QPT) for this model even at finite T. This remarkable property of QD may have important implications for experimental characterization of QPTs when one is unable to reach temperatures below which a QPT can be seen.