Pair density wave order from electron repulsion

Understand

A pair density wave (PDW) is a superconductor whose order parameter is a periodic function of space, without an accompanying spatially-uniform component.

• Since PDWs are not the outcome of a weak-coupling instability of a Fermi liquid, a generic pairing mechanism for PDW order has remained elusive.
• We describe and solve models having robust PDW phases.
• To access the intermediate coupling limit, we invoke large $N$ limits of Fermi liquids with repulsive BCS interactions that admit saddle point solutions.