High-Speed Memory Driven by SFQ Pulses Based on 0-π SQUID

Takeshita, Yuto; Li, Feng; Hasegawa, Daiki; Sano, Kôkichi; Tanaka, Masamitsu; Yamashita, Taro

doi:10.1109/tasc.2021.3060351

Cited by 18 publications

(11 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This implies that information can be stored in the SQUID's different vorticity states. Indeed, fluxbased qubits and memory elements relying on phase-slip physics have already been proposed [20,[26][27][28][29][30]. In this context, an applied magnetic field affects the SQUID energy and is a natural choice of control parameter in a fluxbased memory.…”

Section: Introductionmentioning

confidence: 99%

“…It was demonstrated that applied transport currents flowing in SQUIDs subjected to constant magnetic fields can also induce a transition between different vorticity states [31]. This fact has been explored in proposed zero-field memory elements [26,29], in which the key ingredient is the creation of an asymmetry in the superconducting properties of the SQUID junctions. For a fully superconducting device, we previously demonstrated that the kinetic induction of the junctions may be tuned via nanofabrication, allowing control over the I c (B) characteristics of the device [18].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nanobridge SQUIDs as Multilevel Memory Elements

et al. 2023

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nanobridge SQUIDs as Multilevel Memory Elements

et al. 2023

View full text Add to dashboard Cite

“…Recent research into superconducting single-flux-quantum logic circuits has demonstrated the possibility of improving operating margins and energy consumption by introducing π-junctions into these circuits 9 – 11 . However, despite extensive study of π-junctions for superconducting quantum and classical circuits 2 , 12 – 14 , there have been few reports on device implementation of the π-junction to date 15 – 17 . Therefore.…”

Section: Introductionmentioning

confidence: 99%

Weak spin-flip scattering in Pd89Ni11 interlayer of NbN-based ferromagnetic Josephson junctions

Pham

Sugimoto

Oba

et al. 2022

Sci Rep

View full text Add to dashboard Cite

We studied niobium nitride (NbN)-based π-junctions with a diluted ferromagnetic Pd89Ni11 interlayer (NbN/PdNi/NbN junctions). In the NbN/PdNi/NbN junctions with various PdNi thicknesses, we observed a non-monotonic dependence of the critical currents on PdNi thickness, indicating the effects of the exchange interaction on the superconducting order parameter. From theoretical fitting of the experimental data, we found that the NbN/PdNi/NbN junctions showed a significantly smaller degree of spin-flip scattering in the PdNi interlayer than in the CuNi interlayer of NbN/CuNi/NbN junctions reported previously. The weak spin-flip scattering leads to a longer decay length of the Josephson critical current, so the critical currents were observed over a wide range of PdNi thicknesses (10–40 nm). We also fabricated superconducting quantum interference devices (SQUIDs) including the NbN/PdNi/NbN junction, using a PdNi thickness in which the π-state was expected. A half-flux-quantum shift, as evidence of the π-state, was observed in the magnetic field-dependent critical currents of the SQUIDs. This result represents an important step towards the practical application of NbN-based π-Josephson junctions.

show abstract

“…Recent research into superconducting singleflux-quantum logic circuits has demonstrated the possibility of improving operating margins and energy consumption by introducing π-junctions into these circuits [9][10][11] . However, despite extensive study of π-junctions for superconducting quantum and classical circuits 2,12-14 , there have been few reports on device implementation of the π-junction to date [15][16][17] . Therefore.…”

Section: Introductionmentioning

confidence: 99%

Weak Spin-Flip Scattering in Pd89Ni11 Interlayer of NbN-Based Ferromagnetic Josephson Junctions

Pham

Sugimoto

Oba

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

We studied niobium nitride (NbN)-based π-junctions with a diluted ferromagnetic Pd89Ni11 interlayer (NbN/PdNi/NbN junctions). In the NbN/PdNi/NbN junctions with various PdNi thicknesses, we observed a non-monotonic dependence of the critical currents on PdNi thickness, indicating the effects of the exchange interaction on the superconducting order parameter. From theoretical fitting of the experimental data, we found that the NbN/PdNi/NbN junctions showed a significantly smaller degree of spin-flip scattering in the PdNi interlayer than in the CuNi interlayer of NbN/CuNi/NbN junctions reported previously. The weak spin-flip scattering leads to a longer decay length of the Josephson critical current, so the critical currents were observed over a wide range of PdNi thicknesses (10 – 40 nm). We also fabricated superconducting quantum interference devices (SQUIDs) including the NbN/PdNi/NbN junction, using a PdNi thickness in which the π-state was expected. A half-flux-quantum shift, as evidence of the π-state, was observed in the magnetic field-dependent critical currents of the SQUIDs. This result represents an important step towards the practical application of NbN-based π-Josephson junctions.

show abstract

High-Speed Memory Driven by SFQ Pulses Based on 0-π SQUID

Cited by 18 publications

References 29 publications

Nanobridge SQUIDs as Multilevel Memory Elements

Nanobridge SQUIDs as Multilevel Memory Elements

Weak spin-flip scattering in Pd89Ni11 interlayer of NbN-based ferromagnetic Josephson junctions

Weak Spin-Flip Scattering in Pd89Ni11 Interlayer of NbN-Based Ferromagnetic Josephson Junctions

Contact Info

Product

Resources

About