Integrable Model of Topological SO(5) Superfluidity

TL;DR

This paper introduces a topological SO(5) superfluid model, revealing exotic phases and exact solutions that shed light on superfluid behavior under symmetry constraints and external fields.

Contribution

It presents an exactly solvable model of topological SO(5) superfluidity, connecting symmetry arguments with a detailed quantum phase diagram and novel superfluid mechanisms.

Findings

Discovery of a topological SO(5) superfluid phase.

Exact solution via an SO(5)-symmetric Gaudin model.

Identification of exotic superfluid and metallic phases.

Abstract

Assisted by general symmetry arguments and a many-body invariant, we introduce a phase of matter that constitutes a topological SO(5) superfluid. Key to this finding is the realization of an exactly solvable model that displays some similarities with a minimal model of superfluid $^3$He. We study its quantum phase diagram and correlations, and find exotic superfluid as well as metallic phases in the repulsive sector. At the critical point separating trivial and nontrivial superfluid phases, our Hamiltonian reduces to the globally SO(5)-symmetric Gaudin model with a degenerate ground manifold that includes quartet states. Most importantly, the exact solution permits uncovering of an interesting non-pair-breaking mechanism for superfluids subject to external magnetic fields. Nonintegrable modifications of our model lead to a strong-coupling limit of our metallic phase with a ground-state manifold that shows an extensive entropy.