Remotely induced magnetism in a normal metal using a superconducting spin-valve

Nature Physics. 2016. Vol. 12. P. 57–61.

Flokstra M. G., Satchell N., Kim J., Burnell G., Curran P., Bending S., Cooper J., Kinane C., Langridge S., Isidory A., Pugach N., Eschrig M., Lutkens H., Suter A., Prokcha T., Lee S.

Superconducting spintronics has emerged in the past decade as a promising new field that seeks to open a new dimension
for nanoelectronics by utilizing the internal spin structure of the superconducting Cooper pair as a new degree of
freedom1,2. Its basic building blocks are spin-triplet Cooper pairs with equally aligned spins, which are promoted by
proximity of a conventional superconductor to a ferromagnetic material with inhomogeneous macroscopic magnetization3.
Using low-energy muon spin-rotation experiments we find an unanticipated eect, in contradiction with the existing
theoretical models of superconductivity and ferromagnetism: the appearance of a magnetization in a thin layer of a
non-magnetic metal (gold), separated from a ferromagnetic double layer by a 50-nm-thick superconducting layer ofNb.The
eect can be controlled either by temperature or by using a magnetic field to control the state of the remote ferromagnetic
elements, and may act as a basic building block for a new generation of quantum interference devices based on the spin
of a Cooper pair.

Keywords: superconductivity, proximity effect, ferromagnetic materials