Energy efficient half-flux-quantum circuit aiming at milli-kelvin stage operation

F Li, D Pham, Y Takeshita, M Higashi… - Superconductor …, 2023 - iopscience.iop.org
Abstract Half-flux-quantum (HFQ) circuits are based on 0–π superconducting quantum
interference devices (SQUIDs) and is one of the energy-efficient superconductor digital …

Superconductor digital circuits with π junctions alone

F Li, Y Takeshita, M Tanaka, A Fujimaki - Applied Physics Letters, 2023 - pubs.aip.org
We adopt superconductor/ferromagnet/insulator/superconductor (SFIS) Josephson junctions
(JJs) as both switching JJs and intrinsic π phase shifters in superconductor digital circuits …

Direct observations of π-leaps of superconducting phase differences in π-junction-based SQUIDs

Y Takeshita, F Li, M Higashi, M Tanaka… - Superconductor …, 2023 - iopscience.iop.org
We directly observed π-leaps of superconducting phase differences in π-junction-based
superconducting quantum interference devices (SQUIDs). The SQUIDs studied here are …

Optimization of half-flux-quantum circuits composed of π-shift and conventional Josephson junctions

S Tanemura, Y Takeshita, F Li… - IEEE Transactions …, 2023 - ieeexplore.ieee.org
We report optimization of half-flux-quantum (HFQ) circuits composed of SQUIDs containing
conventional Josephson junctions and π-shift magnetic Josephson junctions. The SQUID …

Superconductor logic implementation with all-jj inductor-free cell library

H Cong, S Razmkhah… - IEEE Transactions …, 2024 - ieeexplore.ieee.org
Single flux quantum (SFQ) technology has garnered significant attention due to its low
switching power and high operational speed. Researchers have been actively pursuing …

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

D Pham, R Sugimoto, K Oba, Y Takeshita, F Li… - Scientific Reports, 2022 - nature.com
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 …

Intrinsic superconducting phase battery

F Li, M Higashi, T Sato, M Tanaka, A Fujimaki - Applied Physics Letters, 2024 - pubs.aip.org
Leveraging the quantization properties inherent in superconductors, we present the
development of an intrinsic superconducting phase battery. This advancement is achieved …

High-density superconductive logic circuits utilizing 0 and π Josephson junctions

S Razmkhah, M Pedram - Engineering Research Express, 2024 - iopscience.iop.org
Superconductor Electronics (SCE) is a fast and power-efficient technology with great
potential for overcoming conventional CMOS electronics' scaling limits. Nevertheless, the …

High-Density Superconductive Logic Circuits Utilizing 0 and Josephson Junctions

S Razmkhah, M Pedram - arxiv preprint arxiv:2308.12474, 2023 - arxiv.org
Superconductor Electronics (SCE) is a fast and power-efficient technology with great
potential for overcoming conventional CMOS electronics' scaling limits. Nevertheless, the …

NbN-based tunnel-type π-junctions for low-power half-flux-quantum circuits

D Pham, F Li, K Oba, Y Takeshita… - Superconductor …, 2024 - iopscience.iop.org
We have developed half-flux-quantum (HFQ) circuits using all-π-junctions formed from an
NbN/AlN/PdNi/NbN (SIFS) structure. The circuits were fabricated using a novel process that …