Weyl-Hubbard System: A Platform to Investigate the Interplay between Topology and Correlations

The interplay between topology and electronic correlations may offer a rich avenue for discovering emergent quantum phenomena in condensed matter systems. In this work, starting from the Weyl-Hubbard system, we investigate the quantum Hall effect to explore the effect of onsite Hubbard correlations on nontrivial Weyl band topology in the presence of an external magnetic field. Within the Gutzwiller approximation, we find the system to undergo multiple topological phase transitions, including two Weyl phases with different pairs of Weyl nodes and a trivial narrow band insulator by tuning on-site Coulomb interaction and external magnetic field. Interestingly, these two Weyl phases can be distinguished by the sign of their chiral Landau levels. We also explore the possible experimental signature of these topological phases and correlation effects by calculating magnetic-field dependent Hall conductivity within the Kubo response theory.