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Proximity and Josephson effects in superconductor - antiferromagnetic Nb / γ-Fe50Mn50 heterostructures

C. Bell·E. J. Tarte·G. Burnell·C. W. Leung·D. -J. Kang·M. G. Blamire
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Abstract

We study the proximity effect in superconductor (S), antiferromagnetic (AF) bilayers, and report the fabrication and measurement of the first trilayer S/AF/S Josephson junctions. The disordered f.c.c. alloy γ-Fe50Mn50 was used as the AF, and the S is Nb. Micron and sub-micron scale junctions were measured, and the scaling of $J_C (d_AF)$ gives a coherence length in the AF of 2.4 nm, which correlates with the coherence length due to suppression of $T_C$ in the bilayer samples. The diffusion constant for FeMn was found to be 1.7 \times 10$^{-4}$ m$^2$ s$^-1$, and the density of states at the Fermi level was also obtained. An exchange biased FeMn/Co bilayer confirms the AF nature of the FeMn in this thickness regime.

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C. Bell, E. J. Tarte, G. Burnell, C. W. Leung, D. -J. Kang, M. G. Blamire. 2003-09-12. Proximity and Josephson effects in superconductor - antiferromagnetic Nb / γ-Fe50Mn50 heterostructures. https://doi.org/10.1103/physrevb.68.144517

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