## Institute for Condensed Matter Theory Seminar: Topology and Interactions: Emergent Mottness at Quarter filling in the Haldane and KM/BHZ models

- Event Type
- Seminar/Symposium
- Sponsor
- The Institute for Condensed Matter Theory
- Location
- 190 ESB
- Date
- Oct 10, 2022 12:00 pm
- Speaker
- Philip Phillips, University of Illinois Urbana Champaign
- Contact
- Janice K Benner
- jbenner@illinois.edu
- Views
- 20
While the recent advances in topology have led to a classification scheme for electronic bands described by the standard theory of metals, a similar scheme has not emerged for strongly correlated systems such as Mott insulators in which a partially filled band carries no current. This talk will address this deficiency by including interactions into the three dominant models for topological states, the Haldane and KM/BHZ models. We show that all of these models

possess a quarter-filled state that is an insulator once the interactions exceed the bandwidth. We obtain this result by solving analytically a model in which the interactions are local in momentum space and then numerically by quantum Monte Carlo simulations on the corresponding Hubbard model. Both yield the same result: For sufficiently large interaction strengths, the quarter-filled Haldane/KM/BHZ models form a topological Mott insulator with ferromagentic correlations with a Chern number of unity. Recent experiments on the anomalous quantum Hall effect in transition metal dichalcogenides are discussed in this context.