Magnetic Josephson junctions are the preferred candidate devices for designing fast and scalable cryogenic memory elements. This is especially the case for rapid single-flux quantum-based superconducting electronics, where the speed mismatch between logic and memory elements have remained a long-standing challenge. In this Letter, we demonstrate a simple tri-layer Josephson memory device using ferromagnetic insulating (FI) GdN-based S/FI/S vertical mesa-type junctions, with reliable nonvolatile memory operation without the need of a shunt resistor at 4.2 K. The characteristic frequency of our devices is approximately 90 GHz, corresponding to an I c R n product of 177  μ V. We demonstrate a thorough study of the parameter spaces required for designing these devices and identify the scope for future improvements that can lead to further miniaturization and higher operating speed of these devices.

1.
D. S.
Holmes
,
S.
Member
,
A. L.
Ripple
, and
M. A.
Manheimer
, “
Energy-efficient superconducting computing—Power budgets and requirements
,”
IEEE Trans. Appl. Supercond.
23
(
1
),
1701610
(
2013
).
2.
K. G.
Fedorov
,
A. V.
Shcherbakova
,
M. J.
Wolf
,
D.
Beckmann
, and
A. V.
Ustinov
, “
Fluxon readout of a superconducting qubit
,”
Phys. Rev. Lett.
112
(
16
),
1
5
(
2014
).
3.
C. H.
Benett
and
D. P.
DiVincenzo
, “
Quantum information and computation
,”
Nature
404
,
247
255
(
2000
).
4.
J. M.
Hornibrook
,
J. I.
Colless
,
I. D.
Conway Lamb
,
S. J.
Pauka
,
H.
Lu
,
A. C.
Gossard
,
J. D.
Watson
,
G. C.
Gardner
,
S.
Fallahi
,
M. J.
Manfra
, and
D. J.
Reilly
, “
Cryogenic control architecture for large-scale quantum computing
,”
Phys. Rev. Appl.
3
(
2
),
1
9
(
2015
).
5.
W.
Chen
,
A. V.
Rylyakov
,
V.
Patel
,
J. E.
Lukens
, and
K. K.
Likharev
, “
Rapid single flux quantum T-Flip flop operating up to 770 GHz
,”
IEEE Trans. Appl. Supercond.
9
(
2
),
3212
3215
(
1999
).
6.
S.
Alam
,
S.
Hossain
, and
S. R.
Srinivasa
, “
Cryogenic memory technologies
,”
Nat. Electron.
6
,
185
198
(
2023
).
7.
S.
Tahara
,
I.
Ishida
,
Y.
Ajisawa
, and
Y.
Wada
, “
Experimental vortex transitional nondestructive read‐out Josephson memory cell
,”
J. Appl. Phys.
65
,
851
856
(
1989
).
8.
S.
Nagasawa
,
K.
Hinode
, and
T.
Satoh
, “
Design of all-dc-powered high-speed single flux quantum random access memory based on a pipeline structure for memory cell arrays
,”
Supercond. Sci. Technol.
19
,
S325
(
2006
).
9.
T. W.
Clinton
and
M.
Johnson
, “
Nonvolatile switchable Josephson junctions
,”
J. Appl. Phys.
85
(
3
),
1637
1643
(
1999
).
10.
C.
Bell
,
G.
Burnell
,
C. W.
Leung
,
E. J.
Tarte
,
D.-J.
Kang
, and
M. G.
Blamire
, “
Controllable Josephson current through a pseudospin-valve structure
,”
Appl. Phys. Lett.
84
(
7
),
1153
1155
(
2004
).
11.
B.
Baek
,
W. H.
Rippard
,
S. P.
Benz
,
S. E.
Russek
, and
P. D.
Dresselhaus
, “
Hybrid superconducting-magnetic memory device using competing order parameters
,”
Nat. Commun.
5
,
1
6
(
2014
).
12.
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
, and
O.
Naaman
, “
Experimental demonstration of a Josephson magnetic memory cell with a programmable π -junction
,”
IEEE Magn. Lett.
9
,
1
5
(
2018
).
13.
A. E.
Madden
,
J. C.
Willard
,
R.
Loloee
, and
N. O.
Birge
, “
Phase controllable Josephson junctions for cryogenic memory phase controllable Josephson junctions for cryogenic memory
,”
Supercond. Sci. Technol.
32
(
1
),
015001
(
2018
).
14.
B.
Baek
,
M. L.
Schneider
,
M. R.
Pufall
, and
W. H.
Rippard
, “
Phase offsets in the critical-current oscillations of Josephson junctions based on Ni and Ni- (Ni 81 Fe 19) x Nb y barriers
,”
Phys. Rev. Appl.
7
(
6
),
064013
(
2017
).
15.
B. M.
Niedzielski
,
T. J.
Bertus
,
J. A.
Glick
,
R.
Loloee
,
W. P.
Pratt
, and
N. O.
Birge
, “
Spin-valve Josephson junctions for cryogenic memory
,”
Phys. Rev. B
97
(
2
),
024517
(
2018
).
16.
E. C.
Gingrich
,
B. M.
Niedzielski
,
J. A.
Glick
,
Y.
Wang
,
D. L.
Miller
,
R.
Loloee
,
W. P.
Pratt
, and
N. O.
Birge
, “
Controllable 0-π Josephson junctions containing a ferromagnetic spin valve
,”
Nat. Phys.
12
(
6
),
564
567
(
2016
).
17.
H.
Sickinger
,
A.
Lipman
,
M.
Weides
,
R. G.
Mints
,
H.
Kohlstedt
,
D.
Koelle
,
R.
Kleiner
, and
E.
Goldobin
, “
Experimental evidence of a φ Josephson junction
,”
Phys. Rev. Lett.
109
(
10
),
107002
(
2012
).
18.
E.
Goldobin
,
H.
Sickinger
,
M.
Weides
,
N.
Ruppelt
,
H.
Kohlstedt
,
R.
Kleiner
, and
D.
Koelle
, “
Memory cell based on a φ Josephson junction
,”
Appl. Phys. Lett.
102
(
24
),
242602
(
2013
).
19.
T.
Golod
,
A.
Iovan
, and
V. M.
Krasnov
, “
Single Abrikosov vortices as quantized information bits
,”
Nat. Commun.
6
(
1
),
1
5
(
2015
).
20.
V. I.
Ruzhitskiy
,
A. G.
Shishkin
,
I. A.
Golovchanskiy
,
I. I.
Soloviev
,
D.
Roditchev
, and
V. S.
Stolyarov
, “
Demonstration of a Josephson vortex-based memory cell with microwave energy-efficient readout
,”
Commun. Phys.
7
,
88
(
2024
).
21.
T.
Golod
,
L.
Morlet-decarnin
, and
V. M.
Krasnov
, “
Word and bit line operation of a 1 × 1 μm2 superconducting vortex-based memory
,”
Nat. Commun.
14
,
4926
(
2023
).
22.
V. V.
Ryazanov
,
V. V.
Bol'ginov
,
D. S.
Sobanin
,
I. V.
Vernik
,
S. K.
Tolpygo
,
A. M.
Kadin
, and
O. A.
Mukhanov
, “
Magnetic Josephson junction technology for digital and memory applications
,”
Phys. Proc.
36
,
35
41
(
2012
).
23.
T. I.
Larkin
,
V. V.
Bol'Ginov
,
V. S.
Stolyarov
,
V. V.
Ryazanov
,
I. V.
Vernik
,
S. K.
Tolpygo
, and
O. A.
Mukhanov
, “
Ferromagnetic Josephson switching device with high characteristic voltage
,”
Appl. Phys. Lett.
100
(
22
),
222601
(
2012
).
24.
L. N.
Karelina
,
R. A.
Hovhannisyan
,
I. A.
Golovchanskiy
,
V. I.
Chichkov
,
A.
Ben Hamida
,
V. S.
Stolyarov
,
L. S.
Uspenskaya
,
S. A.
Erkenov
,
V. V.
Bolginov
, and
V. V.
Ryazanov
, “
Scalable memory elements based on rectangular SIsFS junctions
,”
J. Appl. Phys.
130
(
17
),
173901
(
2021
).
25.
S. K. Y.
Tanaka
, “
Theory of Josephson effect in superconductor-ferromagnetic-insulator-superconductor junction
,”
Phys. C
274
,
357
363
(
1997
).
26.
N.
Yoshida
,
Y.
Tanaka
,
S.
Kashiwaya
, and
J.
Inoue
, “
Current voltage relation for Josephson junctions with ferromagnetic insulator
,”
Phys. B
284–288
,
511
512
(
2000
).
27.
K.
Senapati
,
M. G.
Blamire
, and
Z. H.
Barber
, “
Spin-filter Josephson junctions
,”
Nat. Mater.
10
(
11
),
849
852
(
2011
).
28.
A.
Pal
,
Z. H.
Barber
,
J. W. A.
Robinson
, and
M. G.
Blamire
, “
Pure second harmonic current-phase relation in spin-filter Josephson junctions
,”
Nat. Commun.
5
,
1
5
(
2014
).
29.
A.
Pal
,
K.
Senapati
,
Z. H.
Barber
, and
M. G.
Blamire
, “
Electric-field-dependent spin polarization in GdN spin filter tunnel junctions
,”
Adv. Mater.
25
(
39
),
5581
5585
(
2013
).
30.
D.
Massarotti
,
A.
Pal
,
G.
Rotoli
,
L.
Longobardi
,
M. G.
Blamire
, and
F.
Tafuri
, “
Macroscopic quantum tunnelling in spin filter ferromagnetic Josephson junctions
,”
Nat. Commun.
6
,
6
11
(
2015
).
31.
H. G.
Ahmad
,
V.
Brosco
,
A.
Miano
,
L.
Di Palma
,
M.
Arzeo
,
D.
Montemurro
,
P.
Lucignano
,
G. P.
Pepe
,
F.
Tafuri
,
R.
Fazio
, and
D.
Massarotti
, “
Hybrid ferromagnetic transmon qubit: Circuit design, feasibility, and detection protocols for magnetic fluctuations
,”
Phys. Rev. B
105
(
21
),
214522
(
2022
).
32.
M. G. G.
Blamire
,
A.
Pal
,
Z. H. H.
Barber
, and
K.
Senapati
, “
Spin filter superconducting tunnel junctions
,” in
Proceedings of SPIE
(SPIE,
2012
), p.
84610J
.
33.
J. S.
Moodera
,
T. S.
Santos
, and
T.
Nagahama
, “
The phenomena of spin-filter tunnelling
,”
J. Phys.: Condens. Matter
19
(
16
),
165202
(
2007
).
34.
H. G.
Ahmad
,
R.
Caruso
,
A.
Pal
,
G.
Rotoli
,
G. P.
Pepe
,
M. G.
Blamire
,
F.
Tafuri
, and
D.
Massarotti
, “
Electrodynamics of highly spin-polarized tunnel Josephson junctions
,”
Phys. Rev. Appl.
13
(
1
),
014017
(
2020
).
35.
R. C.
Dynes
and
T. A.
Fulton
, “
Supercurrent density distribution in Josephson junctions
,”
Phys. Rev. B
3
(
9
),
3015
3023
(
1971
).
36.
M.
Weihnacht
, “
Influence of film thickness on D. C. Josephson current
,”
Phys. Status Solidi
32
(
2
),
K169
K172
(
1969
).
37.
K. K.
Likharev
and
V. K.
Semenov
, “
RSFQ logic/memory family: A new Josephson-junction technology for digital systems
,”
IEEE Trans. Appl. Supercond.
1
(
1
),
3
(
1991
).
You do not currently have access to this content.