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arXiv 1401.4075cond-mat.str-el
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Shastry-Sutherland晶格上的Mott转变与反铁磁金属

Mott transition and Antiferromagnetic Metal on Shastry-Sutherland Lattice

Hai-Di Liu, Yao-Hua Chen, Heng-Fu Lin, Hong-Shuai Tao, Wu-Ming Liu

摘要:

Shastry-Sutherland晶格是最简单的几何挫阻体系之一,它通过将单重态放在对角键上而具有精确的本征态,可以在一组层状化合物中实现,引起了理论和实验的兴趣。以往对Shastry-Sutherland晶格的研究大多集中在海森堡模型上。在这里,我们选择的哈伯德模型计算相图的相互作用参数范围很广,并显示相互作用,挫折和温度的竞争效应。在低温下,挫折有利于顺磁金属基态,而相互作用驱动系统的反铁磁绝缘体相。在这两个相之间,有一个反铁磁金属相和一个顺磁绝缘体(这应该是一个价键固体)相产生的挫折和相互作用的竞争。我们的研究结果可能会为进一步深入研究该晶格中的量子相变提供参考。

英文摘要:

The Shastry-Sutherland lattice, one of the simplest systems with geometric frustration, which has an exact eigenstate by putting singlets on diagonal bonds, can be realized in a group of layered compounds and rises both theoretical and experimental interest. Most of the previous studies on the Shastry-Sutherland lattice are focusing on the Heisenberg model. Here we opt for the Hubbard model to calculate phase diagrams over a wide range of interaction parameters, and show the competing effects of interaction, frustration and temperature. At low temperature, frustration is shown to favor a paramagnetic metallic ground state, while interaction drives the system to an antiferromagnetic insulator phase. Between these two phases, there are an antiferromagnetic metal phase and a paramagnetic insulator (which should be a valence bond solid) phase resulting from the competition of the frustration and the interaction. Our results may shed light on more exhaustive studies about quantum phase transitions in this lattice.

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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