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arXiv 1406.0185cond-mat.stat-mechcond-mat.str-el
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双层Heisenberg-伊辛模型的量子临界普适性和奇异角纠缠熵

Quantum Critical Universality and Singular Corner Entanglement Entropy of Bilayer Heisenberg-Ising model

Trithep Devakul, Rajiv R. P. Singh

摘要:

考虑了具有各向异性层内交换耦合的双层量子自旋模型。通过改变各向异性,量子临界现象从XY到海森堡再到伊辛普适类,分别有两个、三个和一个模同时变为无隙。我们用级数展开法计算了系统被二分为两部分时的第二和第三类Renyi纠缠熵。分别计算与角相关的主导面积律项和次主导熵。我们发现明确的证据表明,与角落的对数奇点是普遍的,在每一类。它沿伊辛临界线的系数是在良好的协议与以前获得的横向场伊辛模型。我们的结果提供了强有力的证据的想法,即在纠缠熵的通用条款提供了一个近似的措施,在系统中的低能量自由度。

英文摘要:

We consider a bilayer quantum spin model with anisotropic intra-layer exchange couplings. By varying the anisotropy, the quantum critical phenomena changes from XY to Heisenberg to Ising universality class, with two, three and one modes respectively becoming gapless simultaneously. We use series expansion methods to calculate the second and third Renyi entanglement entropies when the system is bipartitioned into two parts. Leading area-law terms and subleading entropies associated with corners are separately calculated. We find clear evidence that the logarithmic singularity associated with the corners is universal in each class. Its coefficient along the Ising critical line is in excellent agreement with those obtained previously for the transverse-field Ising model. Our results provide strong evidence for the idea that the universal terms in the entanglement entropy provide an approximate measure of the low energy degrees of freedom in the system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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