Demonstration of a Josephson vortex-based memory cell with microwave energy-efficient readout

• Published in: Communications physics Vol. 7; no. 1; pp. 88 - 8
• Main Authors: Kalashnikov, Dmitrii S., Ruzhitskiy, Vsevolod I., Shishkin, Andrey G., Golovchanskiy, Igor A., Kupriyanov, Mikhail Yu, Soloviev, Igor I., Roditchev, Dimitri, Stolyarov, Vasily S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.03.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/119/1003; 639/925/927/1064; Coding; Critical current (superconductivity); Edge barriers; Josephson junctions; Physics; Physics and Astronomy; Superconductivity; Vortices
• ISSN: 2399-3650; 2399-3650
• DOI: 10.1038/s42005-024-01570-4

The ongoing progress of superconducting logic systems with Josephson junctions as base elements requires the development of compatible cryogenic memory. Long enough junctions subject to magnetic field host quantum phase 2 π -singularities—Josephson vortices. Here, we report the realization of the superconducting memory cell whose state is encoded by the number of present Josephson vortices. By integrating the junction into a coplanar resonator and by applying a microwave excitation well below the critical current, we are able to control the state of the system in an energy-efficient and non-destructive manner. The memory effect arises due to the presence of the natural edge barrier for Josephson vortices. The performance of the device is evaluated, and the routes for creating scalable cryogenic memories directly compatible with superconducting microwave technologies are discussed. Developing cryogenic memory is a crucial undertaking in advancing superconducting logic systems. Here, the authors demonstrate the realization of a superconducting memory cell, whose state is encoded by the number of current vortices within a Josephson junction, and the readout employs microwave currents for an energy-efficient, non-destructive process.