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arXiv 0705.3993cond-mat.str-el
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低维量子自旋系统中的矢量手征态

Vector chiral states in low-dimensional quantum spin systems

Raoul Dillenschneider, Jung Hoon Kim, Jung Hoon Han

摘要:

提出了一类具有非零平均矢量自旋手征的精确自旋基态$<Š_i \times Š_j \cdot \hat{z}>$.它是通过在SU(2)不变的Affleck-Kennedy-Lieb-Tasaki(AKLT)态及其母哈密顿量上应用XY平面中自旋算符的非均匀O(2)旋转而获得的。在一维单模近似下研究了S=1时新基态的激发能。激励间隙保持稳健。手性AKLT状态的建设被证明是可能的,在更高的维度。我们还提出了一个一般的想法,以产生矢量手征凝聚的基态作为非均匀O(2)旋转的非手征母态。Dzyaloshinskiii-Moriya相互作用表明非零自旋手征。

英文摘要:

A class of exact spin ground states with nonzero averages of vector spin chirality, $<Š_i \times Š_j \cdot \hat{z}>$, is presented. It is obtained by applying non-uniform O(2) rotations of spin operators in the XY plane on the SU(2)-invariant Affleck-Kennedy-Lieb-Tasaki (AKLT) states and their parent Hamiltonians. Excitation energies of the new ground states are studied with the use of single-mode approximation in one dimension for S=1. The excitation gap remains robust. Construction of chiral AKLT states is shown to be possible in higher dimensions. We also present a general idea to produce vector chirality-condensed ground states as non-uniform O(2) rotations of the non-chiral parent states. Dzyaloshinskii-Moriya interaction is shown to imply non-zero spin chirality.

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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