Experimental demonstration of a Josephson magnetic memory cell with a programmable \pi-junction

I. M. Dayton; T. Sage; E. C. Gingrich; M. G. Loving; T. F. Ambrose; N. P. Siwak; S. Keebaugh; C. Kirby; D. L. Miller; A. Y. Herr; Q. P. Herr; O. Naaman

doi:10.1109/lmag.2018.2801820

arXiv · 1711.01681

Experimental demonstration of a Josephson magnetic memory cell with a programmable \pi-junction

I. M. Dayton·T. Sage·E. C. Gingrich·M. G. Loving·T. F. Ambrose·N. P. Siwak·S. Keebaugh·C. Kirby·D. L. Miller·A. Y. Herr·Q. P. Herr·O. Naaman

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Abstract

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.

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I. M. Dayton, T. Sage, E. C. Gingrich, M. G. Loving, T. F. Ambrose, N. P. Siwak, S. Keebaugh, C. Kirby, D. L. Miller, A. Y. Herr, Q. P. Herr, O. Naaman. 2017-11-06. Experimental demonstration of a Josephson magnetic memory cell with a programmable \pi-junction. https://doi.org/10.1109/lmag.2018.2801820

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