Shapiro steps of superfluid Fermi gases in a ring trap across the BCS--BEC crossover
Abstract
We investigate the transport properties of a superfluid Fermi gas confined in a ring trap with a moving potential barrier across the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) crossover. Employing time-dependent Bogoliubov--de Gennes (BdG) equations, we simulate the dynamics of a Josephson junction biased by both DC and AC currents. Over a wide range of interaction strengths, the barrier-velocity dependence of the chemical potential difference exhibits low-order plateau structures, consistent with Shapiro steps, with fitted levels close to integer multiples of ℏω/2 within the phase-coherent regime. This factor of 1/2 reflects our convention of defining the chemical potential per single fermion in the BdG framework. Microscopic analysis reveals that these fundamental steps originate from synchronized phase slips mediated by periodic soliton generation at the barrier. Our findings clarify the role of interaction regimes in the nonequilibrium phase dynamics of ring-trapped fermionic superfluids and provide microscopic insights relevant to future studies of atomtronic systems with nontrivial topology.
Related
- Dual Shapiro steps and fundamental transconductance in the dc-driven Bloch transistor
- Universal enhancement of the pairing gap in a dilute Fermi superfluid
- Dimensionality of a strongly interacting 2D-3D Fermi-Fermi mixture from the perspective of superfluid instability and excitation properties
- Surface corrections and vortex energetics in the Thomas--Fermi limit of a self-bound unitary Fermi superfluid
- Thermodynamic Signatures of Phase Separation in Mass Imbalanced Fermi Mixtures: Superfluid Density of States and Quasiparticle Specific Heat in the 163Dy 40K Atomic Mixture
BibTeX
@misc{kuriki2026shapiro,
title = {{Shapiro steps of superfluid Fermi gases in a ring trap across the BCS--BEC crossover}},
author = {Hikaru Kuriki and Masaya Kunimi and Tetsuro Nikuni},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.17940},
eprint = {2605.17940},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.17940},
}
RIS
TY - UNPB
TI - Shapiro steps of superfluid Fermi gases in a ring trap across the BCS--BEC crossover
AU - Hikaru Kuriki
AU - Masaya Kunimi
AU - Tetsuro Nikuni
PY - 2026
DA - 2026/09/04
PB - arXiv
DO - 10.48550/arxiv.2605.17940
UR - https://arxiv.org/abs/2605.17940
AB - We investigate the transport properties of a superfluid Fermi gas confined in a ring trap with a moving potential barrier across the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) crossover. Employing time-dependent Bogoliubov--de Gennes (BdG) equations, we simulate the dynamics of a Josephson junction biased by both DC and AC currents. Over a wide range of interaction strengths, the barrier-velocity dependence of the chemical potential difference exhibits low-order plateau structures, consistent with Shapiro steps, with fitted levels close to integer multiples of ℏω/2 within the phase-coherent regime. This factor of 1/2 reflects our convention of defining the chemical potential per single fermion in the BdG framework. Microscopic analysis reveals that these fundamental steps originate from synchronized phase slips mediated by periodic soliton generation at the barrier. Our findings clarify the role of interaction regimes in the nonequilibrium phase dynamics of ring-trapped fermionic superfluids and provide microscopic insights relevant to future studies of atomtronic systems with nontrivial topology.
ER -