Frustrated electrons on a spatially anisotropic triangular lattice: Emergent competition of charge orders and exotic disorders due to thermal fluctuations
Frustrated electrons on a spatially anisotropic triangular lattice: Emergent competition of charge orders and exotic disorders due to thermal fluctuations
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空间各向异性三角晶格上的受挫电子：热波动导致的电荷顺序的新兴竞争和外来无序
DOI：
10.1103/physrevb.90.245115
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Tempei Yoshida and Chisa Hotta
中科院分区：
文献类型：
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作者：
Hazuki Morisaki;Takashi Koretsune;Chisa Hotta;Jun Takeya;Tsuyoshi Kimura and Yusuke Wakabayashi;水島健;Tempei Yoshida and Chisa Hotta
用扩展的四态波茨模型研究了在几何受挫的各向异性三角形晶格上由上下自旋的两种经典粒子组成的系统中相关和热涨落的相互作用。该模型对应于扩展Hubbard模型在四分之一填充时的强耦合极限，该模型已知包含几个相互竞争的电荷有序相以及一种称为弹球液体的奇异量子态。受挫的场址间库仑相互作用与场址库仑相互作用一起产生低能态的宏观简并流形。它们在有限温度下进行熵竞争，出现两种特征态；三倍周期电荷有序态和准一维无序态，称为“良好缺陷态”，其特征是铁电键的系统生成。这两种状态与扩展的Hubbard模型中的三重电荷序和弹球液体具有良好的对应关系，并被发生在三角晶格的三个子晶格中的一个上的部分莫特跃迁所分离。
We study the interplay of correlation and thermal fluctuation in a system consisting of two species of classical particles with up and down spin on a geometrically frustrated anisotropic triangular lattice, described by an extended four-state Potts model. The model corresponds to the strong coupling limit of the extended Hubbard model at quarter-filling, which is known to host several competing charge ordered phases as well as an exotic quantum state called pinball liquid. The frustrated intersite Coulomb interactions together with the on-site Coulomb interaction generate macroscopically degenerate manifolds of low-energy states. They compete entropically at finite temperature and two characteristic states emerge; a threefold periodic charge ordered state and a quasi-one-dimensionally disordered state called “good defect state” characterized by the systematic generation of ferroelectric bonds. The two states show good correspondence with the threefold charge order and the pinball liquid in the extended Hubbard model, and are separated by the partial Mott transition taking place on one of the three sublattices of the triangular lattice.