Chiral superconductors from parent states with non-uniform Berry curvature: Momentum-space vortices and thermal Hall conductivity

Author: Kim, Yong-Baek

Affiliation: University of Toronto

Type: Contributed Talk

Session: Theory: topology, quantum geometry, and unconventional pairing

Date and Time: 22.07.2026, 12:15 - 12:35

We investigate chiral superconductivity emerging from parent electronic states with non-uniform Berry curvature, motivated by recent experiments in rhombohedral graphene multilayers. Using a series of theoretical models —a tunable platform with independently controllable Berry curvature profiles—we solve the full BCS gap equation beyond the weak-coupling limit, allowing pairing across an entire Chern band. We show that a non-uniform Berry curvature fundamentally alters the structure of the superconducting order parameter, enabling the nucleation of momentum-space vortices away from high-symmetry points. These vortices reflect the underlying topology of the normal-state band and are stabilized by strong interactions that enable electrons to probe the full Berry curvature landscape. Furthermore, we establish that the Bogoliubov–de Gennes Chern number is given by the total winding number of vortices enclosed by the Fermi surface. Finally, we discuss experimental signatures in thermal Hall measurements as concrete probes of the momentum-space vortex structures. Our results highlight the crucial role of Berry curvature in shaping chiral superconductivity and offer guiding principles for its identification in systems such as rhombohedral graphene.