Nonreciprocal critical current in multi-element polar superconductors

The superconducting diode effect has been developed as a powerful probe to detect spin-splitting in noncentrosymmetric superconductors. Recent experiments have demonstrated that the zero-field SDE, in which the superconducting current flows only in the forward direction, is effective for evaluating the proximity effect and Rashba effect in noncentrosymmetric superconductors. Zero-field SDEs also have the potential to enable novel nonvolatile memory devices and logic circuits with ultralow power consumption.

In this presentation, we will discuss nonreciprocal critical current in multi-element polar superconductors under and without a magnetic field. In multi-element polar superconductors with ferromagnet/superconductor/ferromagnet structures, the superconducting properties can be controlled by the parallel and antiparallel states of magnetization. We successfully controlled the polarity-reversible and on-off switching of the zero-field SDE. We will also discuss the characteristic behavior of multi-element polar superconductors compared to control samples.