Quantum Matter Seminar by Xinloong Han on July 24, 2023

On July 24th, 2023, quantum matter SG hosted a seminar entitled "Electronic instabilities emerging from higher-order van Hove singularities", and the guest speaker was Xinloong Han, a Postdoctoral Fellow at the Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, China.

Xinloong Han started by introducing van Hove singularity (VHS). Building on the conventional understanding of VHS points, Han introduced the concept of higher-order VHSs, which have recently been explored in ABC-stacked trilayer graphene and twisted bilayer graphene. He elucidated the differences between conventional VHSs and higher-order VHSs, paving the way for a discussion on the enhanced nematicity driven by large flavor number with higher-order VHSs on the square and Kagome lattices.

Towards the conclusion of his talk, Han shed light on the possibility of robust topological superconductivity emerging on the square lattice due to the interplay of spin-orbital coupling and higher-order VHSs. This revelation presented a captivating insight into the advancements in the study of topological superconductors.

Reported by Ching-Kai Chiu