Shafayat Hossain - UCLA

Wednesday 27 Aug 2025, 08:00 → 19:15 US/Eastern

IAMM

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

https://msh-qmind.framer.website/

1 Pick up at hotel

Travel to IAMM.

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

2 Research Meeting

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

10:00 Talk Prep

3 Unconventional quantum states in a kagome superconductor

The kagome lattice offers a unique electronic landscape characterized by flat bands and van Hove singularities—features that enhance electronic correlations and drive instabilities such as superconductivity and charge density waves. As a result, kagome systems host a rich array of emergent many-body quantum phases, some exhibiting unconventional behavior. In this talk, I will present our investigation of the kagome-lattice superconductors AV₃Sb₅ (A = K, Cs), a family of materials that have garnered significant recent attention due to the presence of chiral charge order—potentially breaking time-reversal symmetry—alongside nematicity and superconductivity with an ungapped Fermi surface sheet. First, I will describe how we probed broken symmetries in the normal state using the material’s nonlinear electromagnetic response to circularly polarized light [1]. Next, I will discuss our discovery of two distinct superconducting regimes in CsV₃Sb₅, intriguingly without any clear phase transition between them [2]. These regimes exhibit sharply different characteristics: the low-temperature phase reveals a second superconducting gap and supports low-energy quasiparticles, potentially arising from a nodal gap structure. I will conclude with a discussion of the broader implications of these findings and mention our ongoing efforts to understand these kagome superconductors.

4 Research Meeting

Speaker: Wonhee Ko (University of Tennessee, Knoxville)

12:00 Lunch

Ruixing Zhang, Wonhee Ko

5 Research Meeting

Speaker: Hanno Weitering

6 Research Meeting

Speaker: Steve Johnston (University of Tennessee)

7 Research Meeting

Speaker: Songyang Pu

8 Research Meeting

Speaker: Yishu Wang (University of Tennessee Knoxville)

9 Research Meeting

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

17:45 Dinner

Ruixing Zhang, Hu Miao, Hanno Weitering