Periodic Co/Nb pseudo spin valve for cryogenic memoryстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 4 сентября 2019 г.
Аннотация: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 $F_1$/s/$F_2$/s with $F_1$ and $F_2$ 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)]$_6$ between two superconducting layers of Nb(25nm). Neutron scattering and magnetometry data showed that parallel and antiparallel alignment can be organized by using of magnetic fields of only several tens of Oersted.