Angkun Wu - LANL

Wednesday 26 Feb 2025, 08:00 → 19:15 US/Eastern

IAMM

Abstract: The quantum metric of single-particle wave functions in topological flat bands plays a crucial role in determining the stability of fractional Chern insulating (FCI) states for |C|=1 flatbands. I will discuss how the quantum metric can lead to significant deviations of the many-body Chern number of FCI states from the expected value, which is associated with the partial filling of the single-particle topological flat band. Furthermore, variations of the quantum metric in momentum space induce band dispersion through interactions, affecting the stability of the FCI states. This causes a reentrant transition into the Fermi liquid from the FCI phase as the interaction strength increases. Additionally, I will discuss scenarios involving higher Chern number bands, specifically C=2, where the range of interaction is a key factor. To advance beyond the local curvature description of the quantum metric, I will introduce machine-learning approaches for analyzing quantum geometry of flatbands.

<Speaker Bio>

<Speaker Webpage>:

https://laro.lanl.gov/esploro/profile/angkun_wu/overview

1 Pick up at hotel

Travel to IAMM.

2 Research Meeting

Speaker: Cristian Batista

10:00 Talk Prep

3 Seminar: Quantum Metric and Long-Range Correlations in Topological Flatlands for Fractional Chern Insulators

Abstract: The quantum metric of single-particle wave functions in topological flat bands plays a crucial role in determining the stability of fractional Chern insulating (FCI) states for |C|=1 flatbands. I will discuss how the quantum metric can lead to significant deviations of the many-body Chern number of FCI states from the expected value, which is associated with the partial filling of the single-particle topological flat band. Furthermore, variations of the quantum metric in momentum space induce band dispersion through interactions, affecting the stability of the FCI states. This causes a reentrant transition into the Fermi liquid from the FCI phase as the interaction strength increases. Additionally, I will discuss scenarios involving higher Chern number bands, specifically C=2, where the range of interaction is a key factor. To advance beyond the local curvature description of the quantum metric, I will introduce machine-learning approaches for analyzing quantum geometry of flatbands.

4 Research Meeting

12:00 Lunch

5 Research Meeting

Speaker: Yang Zhang

6 Research Meeting

Speaker: Wonhee Ko (University of Tennessee, Knoxville)

7 Research Meeting

Speaker: Prof. Adrian Del Maestro (University of Tennessee, Knoxville)

8 Research Meeting

Speaker: Dr Songyang Pu

9 Research Meeting

Speaker: Harini Radhakrishnan (University of Tennessee)

10 Research Meeting

Speaker: Ruixing Zhang (Department of Physics and Astronomy, University of Tennessee Knoxville)

11 Research Meeting

Speaker: Nianlong Zou

12 Research Meeting

17:45 Dinner