Wei Yang: Field-theoretic numerical simulations for studying magnetic materials

Institute of Physics

Chinese Academy of Sciences

Date: Wednesday, March 12th, 2025

Location: Elings Hall, room 1601

Time: 12:30 pm - 1:30 pm

Field-theoretic numerical simulations for studying magnetic materials

Abstract: A new phase of matter usually emerges when a given symmetry breaks spontaneously, which can involve charge, spin, valley, and layer degrees of freedom. Twisting graphene multilayer to form a moiré superlattice leads to moiré flat bands where various correlated states are developed. Twisted double bilayer graphene (TDBG) is an electrical displacement field (D) tunable moiré system. Here, I will focus on the high-quality ABBA-stacked TDBG device and present the experimental observations of various correlated phases, such as spin/valley/layer polarized phases, where interplays among correlation, isospin polarization, topology, and scatterings are important. In particular, I will discuss the emergence of heavy fermion features in the strongly correlated regime and novel chiral topological phases at the quantum phase transitions.

Bio: Dr. Wei Yang is an associate professor at the Institute of Physics, Chinese Academy of Sciences (IOP-CAS) in Beijing, China. He received his Ph.D in condensed matter physics from IOP-CAS in 2014, working on graphene-hBN superlattice. He worked as a postdoc from 2014 to 2019, first at École Normale Supérieure and CNRS in Paris on high-frequency noise themometry, then at ICOF-The Institute of Photonic Sciences in Barcelona on quantum transport and nano-mechanics of carbon nanotube. He joined the IOP-CAS as a faculty member in 2019. Currently, he mainly focuses on exploring strongly correlated phases and quantum phase transitions in moiré superlattices.