This study investigates Josephson effects in superconducting junctions with interaction asymmetry across the BCS-BEC crossover. Using a mean-field approach, the authors compute the superconducting order parameter, chemical potential, and pair spectral weight as functions of the interaction parameter. They find that the order parameter peaks near unitarity, while the chemical potential transitions from positive values in the BCS regime to negative values in the BEC regime. The critical current in Josephson junctions with different interaction strengths on each side depends strongly on the asymmetry, exhibiting an interaction-biased Riedel peak phenomenon. The findings provide insights into the interplay between pairing correlations and Josephson transport across the crossover.
Key findings
Order parameter peaks near unitarity in superconducting junctions.
Chemical potential transitions from positive in BCS regime to negative in BEC regime.
Critical current in Josephson junctions with different interaction strengths on each side depends strongly on asymmetry.
Distinct AC response characteristics observed for different asymmetry configurations.
Limitations & open questions
Further research needed to understand the implications for superconducting quantum devices.
Study focuses on mean-field approach, which may not capture all quantum fluctuations.