±¨¸æÌâÄ¿£ºSpin-splitting and supercurrent diode effects in superconducting structures with a ferromagnetic insulator

±¨¸æÈË£ºJason WA Robinson

±¨¸æÕªÒª£ºThe proximity effect in superconductor/ferromagnet (S/F) devices can lead to exotic phenomena, including spin-triplet pairing and the superconducting analogue of spin-valve and diode transport. Although non-reciprocal supercurrents (i.e., a superconducting diode effect) have been observed in different superconducting heterostructures with broken inversion and broken time reversal symmetry via an F layer with spin-orbit coupling, the exact underlying mechanism of the diode effect can be challenging to determine. Here, we report normal state and superconducting state electrical transport measurements of Nb/EuS and EuS/Nb/EuS heterostructures and devices in which Nb is an s-wave superconductor and EuS a ferromagnetic insulator. In the normal and superconducting states, we observe a strong magnetic proximity effect in Nb and an extreme sensitivity of the superconductivity to the micromagnetic state of the EuS layers. Furthermore, we observe an asymmetric flow of flux vortices in Nb/EuS wires, demonstrating superconducting vortex diode effect. 

±¨¸æÈ˽éÉÜ£ºJason Robinson FIMMM has a Professorial Chair in Materials Physics at the University of Cambridge where he is a joint Head of the Department of Materials Science & Metallurgy, Director of the Quantum Materials & Devices Group, and co-director of the Centre for Materials Physics. His experimental research focuses on the development of multifunctional materials and devices, approaching key problems in the fields of spintronics, superconductivity, and quantum technologies. He has made major contributions to these fields, including the discovery of triplet Cooper pairs in hybrid superconductor/magnetic devices and helping to pioneer the field of superconducting spintronics.