Preventing magnet meltdowns before they can start

Science Daily  March 11, 2024 Unlike conventional magnets where a normal zone expands typically quickly, and the stored energy is dissipated across a large volume of the windings, a normal zone in a High-temperature superconductor (HTS) magnet propagates slowly and, thus, can heat up quickly to high temperatures destroying the conductor. At the same time, growing experimental evidence suggests that HTS conductors can operate in a stable dissipative flux flow regime for a substantial range of operational currents before entering an irreversible thermal runaway. Researchers at Lawrence Berkeley National Laboratory proposed a simple criterion for the thermal runaway in HTS […]

Magnetic field turns handed superconductor into liquid crystal-like nematic state

Nanowerk  September 15, 2021 Recent measurements of the resistivity in magic-angle twisted bilayer graphene near the superconducting transition temperature show twofold anisotropy, or nematicity, when changing the direction of an in-plane magnetic field. This was interpreted as strong evidence for exotic nematic superconductivity instead of the widely proposed chiral superconductivity. An international team of researchers (Germany, USA – the Flatiron Institute, Spain) has suggested a surprising connection between the nematic behavior of a superconductor in a magnetic field and its spiral-like ground state in the absence of the field. Their theory could not only explain recent experiments on twisted bilayer […]

Extremely energy efficient microprocessor developed using superconductors

EurekAlert  December 28, 2020 Using the adiabatic quantum-flux-parametron (AQFP), as a building block researchers in Japan have developed and demonstrated a prototype 4-bit AQFP microprocessor called MANA (Monolithic Adiabatic iNtegration Architecture). The AQFP is capable of data processing and data storage, it can operate up to a clock frequency of 2.5 GHz making this on par with today’s computing technologies. They expect this to increase to 5-10 GHz as they make improvements in design methodology and experimental setup. According to the researchers even when taking this cooling overhead into account, the AQFP is still about 80 times more energy-efficient when […]

Device splits and recombines superconducting electron pairs

Phys.org  December 27, 2019 Cooper pair splitting (CPS) can induce nonlocal correlation between two normal conductors that are coupled to a superconductor. An international team of researchers (Japan, China, Sweden) investigated CPS by using a Josephson junction of a gate-tunable ballistic InAs double nanowire. The measured switching current in the two nanowires was significantly larger than the sum of the switching current into the respective nanowires, indicating that interwire superconductivity is dominant compared with intrawire superconductivity. From its dependence on the number of propagating channels in the nanowires, the observed CPS was assigned to one-dimensional electron-electron interaction. The results will […]