Periodic Co/Nb pseudo spin-valve for cryogenic memory
Abstract
We present a new study of magnetic structures with controllable effective exchange energy for Josephson switches and memory. As a basis for a weak link we propose to use a periodic structure comprised of ferromagnetic (F) layers spaced by thin superconductors (s). Our calculations based on Usadel equations show that switching from parallel (P) to antiparallel (AP) alignment of neighboring F layers can lead to a significant enhancement of the critical current through the junction. To control magnetic alignment we propose to use periodic system where unit cell is a pseudo spin-valve /s//s with and two magnetic layers having different coercive fields. In order to check feasibility of controllable switching between AP and P states through the \emph{whole} periodic structure we prepared a superlattice [Co(1.5nm)/Nb(8nm)/Co(2.5nm)/Nb(8nm)] between two superconducting layers of Nb(25nm). Neutron scattering showed that parallel and antiparallel alignment can be organized by using of magnetic fields of only several tens of Oersted.
Cite
@article{arxiv.1809.10165,
title = {Periodic Co/Nb pseudo spin-valve for cryogenic memory},
author = {N. V. Klenov and Yu. N. Khaydukov and S. V. Bakurskiy and I. I. Soloviev and R. Morari and T. Keller and M. Yu. Kupriyanov and A. S. Sidorenko and B. Keimer},
journal= {arXiv preprint arXiv:1809.10165},
year = {2019}
}