Non-Hermitian topological Fermi superfluid near the p-wave unitary limit

We discuss theoretically the non-Hermitian superfluid phase transition in one-dimensional two-component Fermi gases near the p-wave Feshbach resonance accompanied by the two-body loss associated with dipolar relaxation. We point out that this system gives us an opportunity to explore the interplay among various nontrivial properties such as universal thermodynamics at divergent p-wave scattering lengths, the topological phase transi-tion at vanishing chemical potential, and the non-Hermitian Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) transition, in a unified manner. In the BCS phase, the loss-induced superfluid-normal transition occurs when the exceptional point appears in the effective non-Hermitian Hamiltonian. In the BEC phase, the diffusive gapless mode can be regarded as a precursor of the instability of the superfluid state. Moreover, we show that the superfluid state is fragile against the two-body loss near the topological phase transition point.

Automated summary

We discuss the non-Hermitian superfluid phase transition in one-dimensional two-component Fermi gases near the p-wave Feshbach resonance with dipolar relaxation-induced two-body loss. We found that this system provides a unique opportunity to investigate the interplay between various nontrivial properties, including universal thermodynamics at divergent p-wave scattering lengths, topological phase transitions at zero chemical potential, and the non-Hermitian BCS-to-BEC transition. In the BCS phase, the loss-induced superfluid-normal transition occurs at the exceptional point of the effective non-Hermitian Hamiltonian. In the BEC phase, the diffusive gapless mode serves as a precursor to the instability of the superfluid state. Additionally, we demonstrate that the superfluid state is fragile against two-body loss near the topological phase transition point.