We investigate the Mott transition in a two-band Hubbard-Kanamori model using dynamical mean-field theory with the density matrix renormalization group and the numerical renormalization group (NRG) as impurity solvers. The study focuses on the case where the intraorbital and interorbital Coulomb interactions are equal ($U=U_2$) and the Hund's coupling is absent ($J=0$). Our spectral analysis for this case confirms the absence of an orbital-selective Mott transition (OSMT) even in systems with very distinct bandwidths ($t_1$ and $t_2$ parameters for wide and narrow band, respectively) indicating a simultaneous Mott transition occurring in both bands. Notably, the NRG results show the emergence of a pseudo-gap-like feature and a central peak in the narrow band, whose characteristics depend on the hopping parameter $t_2$. These spectral features may act as precursors to OSMT in more realistic systems with finite Hund's coupling ($J>0$). Furthermore, in the Mott insulating phase, the self-energies for both bands diverge, indicating that the Mott transition represents a topological phase transition for both bands. Our results underscore the importance of accurate impurity solvers in capturing the density of states and detailed spectral structures.

Close

PrevNext

View figure in article

• Density of states
• Excited-state quantum phase transitions
• Quantum phase transitions
• Topological phase transition
• Mott insulators
• Strongly correlated systems
• Unconventional superconductors
• Density matrix renormalization group
• Dynamical mean field theory
• Hubbard model
• Numerical Renormalization Group