Proximity-Induced Superconductivity in a Ferromagnetic Semiconductor (In,Fe)As

We observed supercurrent through an n-type ferromagnetic semiconductor (In,Fe)As. For the purpose we prepared S/F/S (S: superconductor, F: ferromagnet) junctions, which exhibited zero resistance up to 1 µm of junction width with critical current over 1 µA below 1 K. The long reach of the superconducting proximity effect suggests that the induced superconductivity is brought about by spin-triplet paring in (In,Fe)As.