Eslam Khalaf (Harvard) - Skyrmion superconductivity

For the schedule of the Harvard/MIT CMT seminar: https://sites.google.com/view/harvardmitcmt/home
Abstract: Inspired by twisted bilayer graphene, I will consider a model of n pairs of tunnel-coupled opposite Chern bands in the presence of strong repulsive interaction with U(n) symmetry. For n=2, I will show that this model develops SU(2)-singlet charge 2e superconductivity in the vicinity of half-filling due to skyrmion pairing. I will show how the properties of this superconductor can be derived within a large N analysis of the non-compact CP1 model. In this setting the superconductor to insulator transition tuned by bandwidth, is the well known deconfined quantum critical point, believed to exhibit an emergent SO(5) symmetry. I will generalize this problem to n=4 and beyond, presenting a parton field theory to study the unusual superconducting phases as well as phase transitions in these models and argue that this setup can be home to exotic deconfined quantum critical points beyond the well-studied SO(5) theory.

Видео Eslam Khalaf (Harvard) - Skyrmion superconductivity канала harvard_mit_cmt_seminar