Supercurrent Diode Effect in Josephson Interferometers with Multiband Superconductors

TL;DR

This paper explores how multiband superconductors with broken time-reversal symmetry can be used in Josephson interferometers to achieve controllable supercurrent rectification, revealing new nonreciprocal effects influenced by magnetic fields.

Contribution

It demonstrates that multiband superconductors with broken time-reversal symmetry enable magnetic control of supercurrent rectification in Josephson devices, with effects unaffected by c-pairing.

Findings

Magnetic field can independently control supercurrent amplitude and direction.

Rectification is unaffected by c}-pairing among bands.

Significant rectification signatures appear in time-reversal symmetry breaking multiband superconductors.

Abstract

We investigate nonreciprocal supercurrent phenomena in superconducting quantum interference devices (SQUIDs) that integrate Josephson junctions with single and multiband order parameters, which may exhibit time-reversal symmetry breaking. Our results show that the magnetic field can independently control both the amplitude and direction of supercurrent rectification, depending on the multiband characteristics of the superconductors involved. We analyze the effects of zero and antiphase ({\pi}) pairing among different bands on the development of nonreciprocal effects and find that the rectification is not influenced by {\pi}-pairing. Furthermore, we demonstrate that incorporating multiband superconductors that break time-reversal symmetry produces significant signatures in rectification. The rectification exhibits an even parity dependence on the magnetic field and the average rectification amplitude across quantum flux multiples does not equal zero. These findings indicate that magnetic flux pumping can be accomplished with time-reversal symmetry broken multiband superconductors by adjusting the magnetic field. Overall, our findings provide valuable insights for identifying and utilizing phases with broken time-reversal symmetry in multiband superconductors.