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arXiv quant-ph/0606207quant-ph
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S=1/2自旋梯中的量子纠缠

Quantum Entanglement in the S=1/2 Spin Ladder with Ring Exchange

Jun-Liang Song, Shi-Jian Gu, Hai-Qing Lin

摘要:

本文利用有限自旋集团精确对角化方法研究了四自旋环交换的$S=1/2$自旋梯中的纠缠度和块-块纠缠。研究了整体相图与基态纠缠的关系。结果表明,不同块大小和几何形状的块-块纠缠体现了系统更丰富的信息。我们发现,由于SU(4)对称性的存在,两格点块-块纠缠的极值点正好位于跃迁点。讨论了块-块纠缠的标度行为。我们的结果表明,块-块纠缠可以作为某些复杂自旋系统中量子相变的一个方便的标记。

英文摘要:

In this paper we study the concurrence and the block-block entanglement in the $S=1/2$ spin ladder with four-spin ring exchange by the exact diagonalization method of finite cluster of spins. The relationship between the global phase diagram and the ground-state entanglement is investigated. It is shown that the block-block entanglement of different block size and geometry manifests richer information of the system. We find that the extremal point of the two-site block-block entanglement on the rung locates a transition point exactly due to SU(4) symmetry at this point. The scaling behavior of the block-block entanglement is discussed. Our results suggest that the block-block entanglement can be used as a convenient marker of quantum phase transition in some complex spin systems.

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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