1:30 pm MCP 201
Models for unconventional superconductivity in moiré materials.
In my talk, I will discuss several examples of superconductivity appearing in stacked Van der Waals structures, and possible mechanisms, with a focus on fluctuations of a time-reversal symmetric intervalley coherent order. In the case of twisted bilayer graphene, I will discuss how coexistence of superconductivity and flavor polarization leads to pairing channels that are guaranteed by symmetry to be entirely band-off-diagonal, with a variety of unusual consequences: most notably, the pairing invariant under all symmetries can have protected nodal lines or be fully gapped, depending on parameters, and the band-off-diagonal chiral d-wave state exhibits transitions between gapped and nodal regions upon varying the chemical potential. In this case, we find fluctuations of an IVC order lead to either a nodal or chiral gapped state, depending on microscopic details, while further including electron-phonon coupling leads to a fully gapped, time-reversal symmetric pairing state.