Superconducting phase coherent electron transport in proximity conical ferromagnets

Phys Rev Lett. 2006 Apr 21;96(15):157002. doi: 10.1103/PhysRevLett.96.157002. Epub 2006 Apr 18.

Abstract

We report superconducting phase-periodic conductance oscillations in ferromagnetic wires with interfaces to conventional superconductors. The ferromagnetic wires were made of Ho, a conical ferromagnet. The distance between the interfaces was much larger than the singlet superconducting penetration depth. We explain the observed oscillations as due to the long-range penetration of an unusual helical triplet component of the order parameter that is generated at the superconductor/ferromagnet interfaces and maintained by the intrinsic rotating magnetization of Ho.