Entanglement in the XY spin chain
Entanglement in the XY spin chain
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DOI：
10.1088/0305-4470/38/13/011
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发表时间：
2005-04-01
期刊：
影响因子：
--
通讯作者：
Korepin, VE
中科院分区：
文献类型：
--
作者：
Its, AR;Jin, BQ;Korepin, VE
本文研究了无限长链XY模型基态的纠缠。继班尼特、伯恩斯坦、Popescu和Schumacher之后，我们使用子系统的熵作为纠缠度的度量。Vidal、Latorre、Rico和Kitaev已经证明，当块的大小增加时，相邻自旋的大块的冯诺依曼熵接近常数。我们评估这种极限熵作为各向异性和横向磁场的函数。我们使用的方法的基础上可积Fredholm算子和Riemann-Hilbert方法。它示出了如何熵变得奇异的相变点。
We consider the entanglement in the ground state of the XY model of an infinite chain. Following Bennett, Bernstein, Popescu and Schumacher, we use the entropy of a sub-system as a measure of entanglement. Vidal, Latorre, Rico and Kitaev have conjectured that the von Neumann entropy of a large block of neighbouring spins approaches a constant as the size of the block increases. We evaluate this limiting entropy as a function of anisotropy and transverse magnetic field. We use the methods based on the integrable Fredholm operators and the Riemann-Hilbert approach. It is shown how the entropy becomes singular at the phase transition points.