论文标题
一维哈伯德模型中的特殊点
Exceptional points in the one-dimensional Hubbard model
论文作者
论文摘要
非热门现象提供了一种新颖的方法，可以在存在相互作用的情况下分析和解释光谱。使用密度 - 矩阵重归其化组（DMRG），我们证明了具有手性对称性的1D交替Hubbard链的一颗粒子绿色功能的特殊点，并在光谱中以零频率为零频率。它们是由于有效的哈密顿量描述了绿色功能的非热性，仅在有限温度下出现。它们很健壮，可以在拓扑上以零零数字为特征。这种效果说明了温度在1D中具有很强效果的情况，超出了光谱特征的简单扩展。最后，我们证明了即使在两粒子绿色的功能（电荷结构因子）中也出现了特殊点，在这些功能（电荷结构因子）中，有效的汉密尔顿很难确定，但由于独特的对称约束而偏离了零频率。
Non-Hermitian phenomena offer a novel approach to analyze and interpret spectra in the presence of interactions. Using the density-matrix renormalization group (DMRG), we demonstrate the existence of exceptional points for the one-particle Green's function of the 1D alternating Hubbard chain with chiral symmetry, with a corresponding Fermi arc at zero frequency in the spectrum. They result from the non-Hermiticity of the effective Hamiltonian describing the Green's function and only appear at finite temperature. They are robust and can be topologically characterized by the zeroth Chern number. This effect illustrates a case where temperature has a strong effect in 1D beyond the simple broadening of spectral features. Finally, we demonstrate that exceptional points appear even in the two-particle Green's function (charge structure factor) where an effective Hamiltonian is difficult to establish, but move away from zero frequency due to a distinct symmetry constraint.
