We experimentally demonstrate the operation of a Josephson magnetic random access memory unit cell, built with a Ni_80Fe_20/Cu/Ni pseudo spin-valve Josephson junction with Nb electrodes and an integrated readout SQUID in a fully planarized Nb fabrication process. We show that the parallel and anti-parallel memory states of the spin-valve can be mapped onto a junction equilibrium phase of either zero or pi by appropriate choice of the ferromagnet thicknesses, and that the magnetic Josephson junction can be written to either a zero-junction or pi-junction state by application of write fields of approximately 5 mT. This work represents a first step towards a scalable, dense, and power-efficient cryogenic memory for superconducting high-performance digital computing.
@article{arxiv.1711.01681,
title = {Experimental demonstration of a Josephson magnetic memory cell with a programmable \pi-junction},
author = {I. M. Dayton and T. Sage and E. C. Gingrich and M. G. Loving and T. F. Ambrose and N. P. Siwak and S. Keebaugh and C. Kirby and D. L. Miller and A. Y. Herr and Q. P. Herr and O. Naaman},
journal= {arXiv preprint arXiv:1711.01681},
year = {2018}
}
Comments
5 pages, 5 figures, accepted by IEEE Magnetics Letters