Andrea Young

 

Department of Physics, UC Santa Barbara

 

 

Abstract.– I will introduce the electronic structure of rhombohedral trilayer graphene, which hosts a saddle point van Hove singularity.  Experiments probing thermodynamic density of states and electronic transport show that as the density is tuned towards the van Hove singularity, a cascade of ferromagnetic transitions occurs between states with broken spin and/or valley symmetries, including “half-metal” and “quarter-metal” states with a variety of Fermi surface topologies.  Unexpectedly, we find superconducting states in the proximity of several of these magnetic transitions, including one superconducting state that emerges from a spin polarized half metal.  I will review possible origins for these superconducting states.