Yinjie Guo: Superconductivity in twisted bilayer WSe2

Abstract: Moiré transition metal dichalcogenides (TMDs) offer a rich platform for exploring correlated electronic states in flat bands. In this talk, I will first discuss our experimental discovery of superconductivity in 5° twisted WSe₂ (tWSe₂) and its close proximity to a Fermi-surface reconstruction (FSR) associated with antiferromagnetic ordering. This result establishes that moiré flat-band superconductivity extends beyond graphene structures. I will then present the superconducting phase diagrams across twist angles from 3.8° to 5°. The superconducting state changes smoothly across this range while remaining closely connected to the FSR, providing new insights into its origin and dependence on correlation strength. Our results place these systems in a crossover between weak and strong correlations, establishing twisted TMDs as a unique platform for studying correlated phases as the ratio of interaction strength to bandwidth is varied.

Bio: Yinjie Guo is currently a PhD student in Physics Department at Columbia University, working in Cory Dean’s group. Her research focuses on experimental condensed matter physics, particularly exploring strongly correlated electronic phenomena in two-dimensional materials, through a combination of complex device fabrication and low-temperature transport measurements.