English

Nonequilibrium phase transition of dissipative fermionic superfluids: Case study of multi-terminal Josephson junctions

Quantum Gases 2026-04-02 v1 Statistical Mechanics Strongly Correlated Electrons Superconductivity Quantum Physics

Abstract

We investigate nonequilibrium dynamics of a triad of fermionic superfluids connected via Josephson junctions, following sudden switch-on of two-body loss in one of the three superfluids. By formulating the dissipative BCS theory for the Lindblad equation, we find that the superfluid order parameter exhibits a phase rotation, thereby giving rise to three types of dc Josephson currents corresponding to different junctions. We demonstrate that, when the tunneling amplitude V31V_{31} between superfluids without two-body loss is weak, two-step nonequilibrium dynamical phase transition (NDPT) characterized by the vanishing dc Josephson currents occurs: dissipation first induces the NDPT by making one dc Josephson current finite, while further increasing dissipation makes this remaining dc Josephson current vanish. By contrast, when V31V_{31} is strong, dissipation induces the NDPT in which all dc Josephson currents simultaneously vanish. An analytical study based on a simplified model further supports this observation.

Keywords

Cite

@article{arxiv.2604.00574,
  title  = {Nonequilibrium phase transition of dissipative fermionic superfluids: Case study of multi-terminal Josephson junctions},
  author = {Soma Takemori and Kazuki Yamamoto},
  journal= {arXiv preprint arXiv:2604.00574},
  year   = {2026}
}

Comments

14 pages, 10 figures