标题： 双带Hubbard-Kanamori模型的低能结构与拓扑特性 显示英文标题

标题： Low-energy structure and topology of the two-band Hubbard-Kanamori model

摘要： 我们使用含密度矩阵重正化群(DMRG)和数值重正化群(NRG)作为杂质求解器的动力学平均场理论(DMFT)，研究了两带Hubbard-Kanamori模型中的Mott转变。我们的研究集中在轨道内库仑相互作用和轨道间库仑相互作用相等(U=U2)且不存在洪德耦合(J=0)的情况下。光谱分析确认了即使在宽带差异显著的系统中(宽带和窄带的跃迁积分分别为t1和t2)，也没有出现轨道选择性Mott转变(OSMT)，这表明两个带同时发生了Mott转变。值得注意的是，NRG结果显示，在窄带中出现了类似伪隙特征和中心峰，其特性取决于跃迁参数t2。这些光谱特征可能是更现实的有限洪德耦合(J>0)系统中OSMT的前兆。此外，在Mott绝缘相中，两个带的自能发散，表明Mott转变代表了一个拓扑相变。我们的结果强调了精确的杂质求解器在捕捉态密度和详细光谱结构方面的重要作用。 显示英文摘要

摘要： We investigate the Mott transition in a two-band Hubbard-Kanamori model using Dynamical Mean-Field Theory (DMFT) with the Density Matrix Renormalization Group (DMRG) and the Numerical Renormalization Group (NRG) as impurity solvers. Our study focuses on the case where the intraorbital and interorbital Coulomb interactions are equal (U = U2) and the Hund's coupling is absent (J = 0). Spectral analysis confirms the absence of an orbital-selective Mott transition (OSMT), even in systems with significantly different bandwidths (t1 and t2 for the wide and narrow bands, respectively), indicating a simultaneous Mott transition in both bands. Notably, the NRG results reveal the emergence of a pseudo-gap-like feature and a central peak in the narrow band, whose characteristics depend on the hopping parameter t2. These spectral features may serve as precursors to OSMT in more realistic systems with finite Hund's coupling (J > 0). Furthermore, in the Mott insulating phase, the self-energies of both bands diverge, suggesting that the Mott transition represents a topological phase transition. Our results highlight the crucial role of accurate impurity solvers in capturing the density of states and detailed spectral structures.