Dynamic Spectral Weight Transfer in the Multi-Orbital Hatsugai-Kohmoto Model

The Hatsugai-Kohmoto (HK) model provides a rich testbed for Mott physics due to its exact diagonalizability in momentum space [1,2]. Extending HK to multiple orbitals introduces non-trivial commutators between the interaction and kinetic terms. We show that the orbital HK model exhibits Dynamical Spectral Weight Transfer under doping away from the Mott insulating phase, which indicates the presence of delocalized modes. We postulate that the orbital HK model provides a bridge between band HK and the Hubbard model due to the introduction of momentum state mixing.

1) Phillips, P.W., Yeo, L. & Huang, E.W. Exact theory for superconductivity in a doped Mott insulator. Nat. Phys. 16, 1175–1180 (2020)

2) Mai, P., Zhao, J., Feldman, B.E. et al. 1/4 is the new 1/2 when topology is intertwined with Mottness. Nat Commun 14, 5999 (2023)