Pt and CoB trilayer Josephson $$pi $$ π junctions with perpendicular magnetic anisotropy

Pt and CoB trilayer Josephson $$pi $$ π junctions with perpendicular magnetic anisotropy

Blog Article

Abstract We report on the electrical transport properties of Nb based Josephson junctions with Pt/Co $$_{68}$$ 68 B $$_{32}$$ 32 /Pt ferromagnetic barriers.The barriers exhibit perpendicular magnetic anisotropy, which has the main advantage for potential applications over magnetisation in-plane systems of not affecting the Fraunhofer response of the junction.In addition, we report that there is no magnetic dead layer at the Pt/Co Parts $$_{68}$$ 68 B $$_{32}$$ 32 interfaces, allowing us to study barriers with ultra-thin Co $$_{68}$$ 68 B $$_{32}$$ 32.In the junctions, we observe that the magnitude of the critical current oscillates with increasing thickness of the Co $$_{68}$$ 68 B $$_{32}$$ 32 strong ferromagnetic alloy layer.

The oscillations are attributed to the ground state phase difference across the junctions being modified from zero to $$pi $$ π.The Wooden Blocks multiple oscillations in the thickness range $$0.2~leqslant ~d_ ext {CoB}~leqslant ~1.4$$ 0.

2 ⩽ d CoB ⩽ 1.4  nm suggests that we have access to the first zero- $$pi $$ π and $$pi $$ π -zero phase transitions.Our results fuel the development of low-temperature memory devices based on ferromagnetic Josephson junctions.