Abstract
One of the primary drawbacks limiting the use of superconductive electronics is the lack of fast and dense memory capable of operating within a cryogenic environment. Recent research suggests the use of cryogenic spin-based memory—magnetic tunnel junctions and spin valves. In this chapter, a sense amplifier topology for a spin-based cryogenic memory cell is proposed and described. The nanocryotron (nTron) device is used as a driver for a spin-based memory element—the cryogenic orthogonal spin transfer device. A clocked DC-to-SFQ converter is used as a sense amplifier to resolve small differences in the readout current. The sense amplifier produces a variable number of SFQ pulses to represent different analog states by passing or blocking input clock pulses. This clock is derived from the system clock by synchronizing the read pulse to the same clock signal. These output pulses are counted and converted into a binary form. The sense amplifier exploits the specific shape of the nTron output waveform characterized by an L/R time constant to achieve the resolution of low magnetoresistance (MR) memory cells and is adaptable to different nTron sizes, bias currents, and spin-based devices. The dynamic power dissipation and resolution of the sense amplifier can be adjusted by the frequency of the applied clock signal, allowing the resolution to be reduced for high MR devices. The sense amplifier consists of two Josephson junctions, requiring little area, particularly in comparison to a standard nTron device, and can therefore be connected to each column of the memory array.
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References
F. Shanehsazzadeh, T. Jabbari, F. Qaderi, M. Fardmanesh, Integrated monolayer planar flux transformer and resonator tank circuit for high- T\({ }_C\) RF-SQUID magnetometer. IEEE Trans. Appl. Supercond. 27(4), 1–4 (2017)
K.K. Likharev, V.K. Semenov, RSFQ logic/memory family: a new Josephson-junction technology for sub-terahertz-clock-frequency digital systems. IEEE Trans. Appl. Supercond. 1(1), 3–28 (1991)
O.A. Mukhanov, D. Gupta, A.M. Kadin, V.K. Semenov, Superconductor analog-to-digital converters. Proc. IEEE 92(10), 1564–1584 (2004)
T. Jabbari, E.G. Friedman, SFQ/DQFP interface circuits. IEEE Trans. Appl. Supercond. 33(5), 1–5 (2023)
R. Bairamkulov, T. Jabbari, E.G. Friedman, QuCTS – single flux quantum clock tree synthesis. IEEE Trans. Comput. Aided Des. Integr. Circuits Syst. 41(10), 3346–3358 (2022)
T. Jabbari, G. Krylov, J Kawa, E.G. Friedman, Splitter trees in single flux quantum circuits. IEEE Trans. Appl. Supercond. 31(5), 1302606 (2021)
A.N. McCaughan, K.K. Berggren, A superconducting-nanowire three-terminal electrothermal device. Nano Lett. 14(10), 5748–5753 (2014)
G. Krylov, E.G. Friedman, Sense amplifier for spin-based cryogenic memory cells. IEEE Trans. Appl. Supercond. 29(5), 1–4 (2019). Art no. 1501804
G. Krylov, E.G. Friedman, Behavioral verilog-A model of superconductor-ferromagnetic transistor, in Proceedings of the IEEE International Symposium on Circuits and Systems (2018)
G. Krylov, E.G. Friedman, Partitioning RSFQ circuits for current recycling. IEEE Trans. Appl. Supercond. 31(5), 1–6 (2021)
G. Krylov, E.G. Friedman, Design methodology for distributed large-scale ERSFQ bias networks. IEEE Trans. Very Large Scale Integr. (VLSI) Syst. 28(11), 2438–2447 (2020)
G. Krylov, E.G. Friedman, Asynchronous dynamic single flux quantum majority gates. IEEE Trans. Appl. Supercond. 30(5), 1–7 (2020). Art no. 1300907
T. Jabbari, G. Krylov, E.G. Friedman, Logic locking in single flux quantum circuits. IEEE Trans. Appl. Supercond. 31(5) (2021)
Y. Mustafa, T. Jabbari, S. Köse, Emerging attacks on logic locking in SFQ circuits and related countermeasures. IEEE Trans. Appl. Supercond. 32(3), 1–8 (2022)
T. Jabbari, H. Zandi, F. Foroughi, A. Bozbey, M. Fardmanesh, Investigation of readout cell configuration and parameters on functionality and stability of bi-directional RSFQ TFF. IEEE Trans. Appl. Supercond. 26(3), 1–5 (2016)
G. Krylov, E.G. Friedman, Design for testability of SFQ circuits. IEEE Trans. Appl. Supercond. 27(8), 1–7 (2017)
I.I. Soloviev, N.V. Klenov, S.V. Bakurskiy, M.Y. Kupriyanov, A.L. Gudkov, A.S. Sidorenko, Beyond Moore’s technologies: operation principles of a superconductor alternative. Beilstein J. Nanotechnol. 8, 2689–2710 (2017)
L. Ye, D.B. Gopman, L. Rehm, D. Backes, G. Wolf, T. Ohki, A.F. Kirichenko, I.V. Vernik, O.A. Mukhanov, A.D. Kent, Spin-transfer switching of orthogonal spin-valve devices at cryogenic temperatures. J. Appl. Phys. 115(17), 17C725 (2014)
S.R. Whiteley, WRspice Reference Manual [Online]. Available: http://www.wrcad.com/manual/wrsmanual.pdf
A.J. Kerman, E.A. Dauler, W.E. Keicher, J.K.W. Yang, K.K. Berggren, G. Gol’tsman, B. Voronov, Kinetic-inductance-limited reset time of superconducting nanowire photon counters. Appl. Phys. Lett. 88(11), 111116 (2006)
Q. Liu, T. Van Duzer, X. Meng, S.R. Whiteley, K. Fujiwara, T. Tomida, K. Tokuda, N. Yoshikawa, Simulation and measurements on a 64-kbit hybrid Josephson-CMOS memory. IEEE Trans. Appl. Supercond. 15(2), 415–418 (2005)
J.K.W. Yang, A.J. Kerman, E.A. Dauler, V. Anant, K.M. Rosfjord, K.K. Berggren, Modeling the electrical and thermal response of superconducting nanowire single-photon detectors. IEEE Trans. Appl. Supercond. 17(2), 581–585 (2007)
J.R. Clem, V.G. Kogan, Kinetic impedance and depairing in thin and narrow superconducting films. Phys. Rev. B 86, 174521 (2012)
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Krylov, G., Jabbari, T., Friedman, E.G. (2024). Sense Amplifier for Spin-Based Cryogenic Memory Cell. In: Single Flux Quantum Integrated Circuit Design. Springer, Cham. https://doi.org/10.1007/978-3-031-47475-0_9
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DOI: https://doi.org/10.1007/978-3-031-47475-0_9
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