Frustrated Cooper pairing and the $f$-wave supersolidity

TL;DR

This paper introduces frustrated Cooper pairing in non-bipartite lattices, leading to novel supersolid states with non-uniform phases, specifically an $f$-wave symmetry supersolid in optical lattices with ultra-cold fermions.

Contribution

It proposes a new type of frustrated Cooper pairing mechanism resulting in exotic supersolid states with non-uniform phases and introduces the $f$-wave supersolidity in triangular optical lattices.

Findings

Frustrated Cooper pairing leads to non-uniform phase and density distributions.

The $f$-wave supersolid state naturally occurs in the $p$-orbital band.

Unconventional supersolid with $f$-wave symmetry observed in triangular lattices.

Abstract

Geometric frustration in quantum magnetism refers to that magnetic interactions on different bonds cannot be simultaneously minimized. The usual Cooper pairing systems favor the uniform distribution of the pairing phase among lattice sites without frustration. In contrast, we propose "frustrated Cooper pairing" in non-bipartite lattices which leads to frustrated supersolid states with non-uniform distributions of the Cooper pair phase and density. This exotic pairing state naturally occurs in the $p$-orbital band in optical lattices with ultra-cold spinless fermions. In the triangular lattice, it exhibits an unconventional supersolid state with the $f$-wave symmetry.