Phase diagram of the magnetic state obtained from a two-particle self-consistent analysis of the half-filled Hubbard model on a honeycomb lattice
Phase diagram of the magnetic state obtained from a two-particle self-consistent analysis of the half-filled Hubbard model on a honeycomb lattice
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DOI：
10.1088/1742-6596/969/1/012095
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发表时间：
2018-03
期刊：
影响因子：
--
通讯作者：
H. Aizawa
中科院分区：
文献类型：
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作者：
H. Aizawa
基于蜂窝晶格半填充Hubbard模型的磁性，我们采用两粒子自洽（TPSC）方法计算了自旋磁化率并估计了磁跃迁.对角化的自旋磁化率矩阵在Q = 0时具有最大值，这表明在晶胞之间形成了均匀的磁序。相同子晶格和不同子晶格之间的自旋磁化率符号相反。因此，该系统中出现了反铁磁状态。我们计算了斯托纳因子的温度依赖性并估计了临界温度外推。通过应用相同的分析，几个值的现场相互作用，我们提出了在蜂窝晶格上的半填充Hubbard模型的磁态的相图。根据相图，临界现场相互作用Uc/t（高于该临界现场相互作用，在基态发生磁性）可以估计为约3.81。
Motivated by the fascinating magnetic properties in the half-filled Hubbard model on a honeycomb lattice, we calculate the spin susceptibility and estimate the magnetic transition by applying the two-particle self-consistent (TPSC) method. The diagonalized spin-susceptibility matrix has its maximum at Q = 0, which indicates that an uniform magnetic order develops between the unit cells. The sign of the spin susceptibility between same sublattices is opposite to that between different sublattices. Therefore, an antiferromagnetic state develops in this system. We calculate the temperature dependence of the Stoner factor and estimate the critical temperature extrapolation. By applying the same analysis to several values of on-site interactions, we present the phase diagram of the magnetic state in the half-filled Hubbard model on a honeycomb lattice. Based on the phase diagram, the critical on-site interaction Uc/t above which magnetism occurs at the ground state can be estimated as being approximately 3.81.