Publications

Spin-triplet supercurrent in Josephson junctions containing a synthetic antiferromagnet with perpendicular magnetic anisotropy

Click, J.A.; Edwards, S.E.; Korucu, D.K.; Aguilar, V.A.; Niedzielski, B.M.; Loloee, R.L.; Pratt, W.P.; Birge, N.O.; Kotula, Paul G.; Missert, Nancy A.

In this paper, we present measurements of Josephson junctions containing three magnetic layers with noncollinear magnetizations. The junctions are of the form

, where

is superconducting Nb,

is either a thin Ni or Permalloy layer with in-plane magnetization,

is the normal metal Cu,

is a synthetic antiferromagnet with magnetization perpendicular to the plane, composed of Pd/Co multilayers on either side of a thin Ru spacer, and

is a thin Ni layer with in-plane magnetization. The supercurrent in these junctions decays more slowly as a function of the

-layer thickness than for similar spin-singlet junctions not containing the

and

layers. The slower decay is the prime signature that the supercurrent in the central part of these junctions is carried by spin-triplet pairs. Finally, the junctions containing

Permalloy are suitable for future experiments where either the amplitude of the critical current or the ground-state phase difference across the junction is controlled by changing the relative orientations of the magnetizations of the

and

layers.