​INTERPLAY BETWEEN SUPERCONDUCTIVITY AND FERROMAGNETISM IN A VAN DER WAALS SUPERCONDUCTOR

Abstract

Ferromagnetic superconductors offer tantalizing possibilities for topological qubits. Yet, triplet pairing rarely exists in solid-state systems due to the competition between superconductivity and magnetism. Despite the prospects with the heavy-fermion compounds and engineered heterostructures, a complete synergy between the superconducting and ferromagnetic orders remains to be seen at device level. Here, we realize a direct implantation of dilute ferromagnetism into a van der Waals superconducting spin valve. In the superconducting regime, we observe a tunable Kondo effect, which re-enters into a superconducting phase under high magnetic field, and a switch of the tunneling magnetoresistance inside the superconducting energy gap. These findings suggest ferromagnetism is induced in our superconducting system, where spin-triplet pairing likely occurs below the Curie temperature. We further demonstrate a tunable long-range diffusion of the spin-polarized supercurrents via a non-local geometry and highlight its promise for superconducting spintronics.