Controlling the proximity effect in a Co/Nb multilayer: the properties of electronic transport

Sergey Bakurskiy; Mikhail Kupriyanov; Nikolay V Klenov; Igor Soloviev; Andrey Schegolev; Roman Morari; Yury Khaydukov; Anatoli S Sidorenko

doi:10.3762/bjnano.11.118

Controlling the proximity effect in a Co/Nb multilayer: the properties of electronic transport

Beilstein J Nanotechnol. 2020 Sep 7:11:1336-1345. doi: 10.3762/bjnano.11.118. eCollection 2020.

Authors

Sergey Bakurskiy¹, Mikhail Kupriyanov¹, Nikolay V Klenov^{1

2

3}, Igor Soloviev^{1

4}, Andrey Schegolev^{2

3}, Roman Morari^{5

6}, Yury Khaydukov^{1

7}, Anatoli S Sidorenko^{6

8}

Affiliations

¹ Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow, 119991, Russia.
² Lomonosov Moscow State University, Physics Department, Moscow, 119991, Russia.
³ Moscow Technical University of Communication and Informatics (MTUCI), 111024 Moscow, Russia.
⁴ Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia.
⁵ Moscow Institute of Physics and Technology, State University, Dolgoprudny, Moscow Region 141700, Russia.
⁶ Institute of Electronic Engineering and Nanotechnologies ASM, MD2028 Kishinev, Moldova.
⁷ Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569 Stuttgart, Germany.
⁸ Laboratory of Functional Nanostructures, Orel State University named after I.S. Turgenev, 302026, Orel, Russia.

Abstract

We present both theoretical and experimental investigations of the proximity effect in a stack-like superconductor/ferromagnetic (S/F) superlattice, where ferromagnetic layers with different thicknesses and coercive fields are made of Co. Calculations based on the Usadel equations allow us to find the conditions at which switching from the parallel to the antiparallel alignment of the neighboring F-layers leads to a significant change of the superconducting order parameter in superconductive thin films. We experimentally study the transport properties of a lithographically patterned Nb/Co multilayer. We observe that the resistive transition of the multilayer structure has multiple steps, which we attribute to the transition of individual superconductive layers with the critical temperature, T _c, depending on the local magnetization orientation of the neighboring F-layers. We argue that such superlattices can be used as tunable kinetic inductors designed for artificial neural networks representing the information in a "current domain".

Keywords: cryogenic computing; spin-valve; superconducting neural network; superconducting spintronics.

Grants and funding

We acknowledge the partial financial support from Grant No. 20-69-47013 of the Russian Science Foundation (theoretical approach and calculations). R. Morari is grateful for the support from the Russian Ministry of Education and Science within the program 5top100. A. Sidorenko would like to thank the support from the European Union H2020-WIDESPREAD-05-2017-Twinning program (“SPINTECH” project under the grant agreement Nr. 810144).