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arXiv · 1401.4075

Mott transition and Antiferromagnetic Metal on Shastry-Sutherland Lattice

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

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.

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Hai-Di Liu, Yao-Hua Chen, Heng-Fu Lin, Hong-Shuai Tao, Wu-Ming Liu. 2014-01-16. Mott transition and Antiferromagnetic Metal on Shastry-Sutherland Lattice. https://doi.org/10.1038/srep04829

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