Supercurrent diode effect in Josephson interferometers with multiband superconductors

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 the direction of supercurrent rectification, depending on the multiband characteristics of the superconductors involved. We analyze the effects of in-phase (zero) and antiphase (π) pairing among different bands on the development of nonreciprocal effects and find that the rectification is not influenced by π-pairing. Furthermore, we demonstrate that incorporating multiband superconductors that break time-reversal symmetry produces significant signatures in rectification. The rectification exhibits an even 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 results provide valuable insights for identifying and utilizing phases with broken time-reversal symmetry in multiband superconductors. Nonreciprocal supercurrent phenomena and the corresponding diode effect in dc SQUIDs based on Josephson junctions with single and multiband superconductors are studied. It is shown that magnetic fields can independently control supercurrent rectification’s amplitude and direction, particularly in superconductors with broken time-reversal symmetry.