Analysis: Science & Technology — 17 October 2026
One-atom-high steps guide superconducting vortices 1,000 times more easily
Researchers at Japan’s Research Center for Materials Nanoarchitectonics (MANA, NIMS) report that steps only one atom high on an ultrathin superconductor act as rails for quantum vortices. Four-terminal resistance measurements showed the vortices moved more than 1,000 times more easily along the steps than across them at intermediate magnetic fields. Scanning tunneling microscopy confirmed parallel steps with vortices sitting on them. The guiding effect could be tuned by changing temperature or magnetic field.
Superconductors carry current without resistance below a critical temperature, but magnetic flux enters as vortices whose motion produces resistance and can degrade devices. Steering those vortices in two-dimensional films has been especially difficult. Led by Takashi Uchihashi, the team studied an atomic-layer superconductor on a vicinal surface and published anisotropic Josephson-vortex transport in Physical Review B.
Between about 0.10 and 0.20 tesla they observed one-dimensional, pinning-free flow along the steps. At the lowest temperatures, motion appeared to proceed by quantum tunneling through barriers that would stop classical objects. Whether the geometry can be engineered at device scale, and whether it will cut heat and residual resistance in working circuits, remains unproven.
Sources: ScienceDaily; Physical Review B (Qian et al., 2026).
New calculation may close the gallium neutrino anomaly without sterile neutrinos
A collaboration of Italian physicists reports in Physical Review Letters that a revised treatment of the electron–nucleus interaction can account for the long-standing ~20% shortfall of electron neutrinos captured on gallium-71. Their numerical result matches the observed capture rate, removing the need to invoke oscillations into sterile neutrinos. Lead author Matteo Cadeddu of INFN said he had never been convinced that sterile neutrinos were the only explanation.
The gallium anomaly dates to the 1990s and was stated clearly in 2007; the Baksan experiment reaffirmed it in 2022. In the reaction, an electron neutrino converts ⁷¹Ga to ⁷¹Ge via a charged-current weak interaction. A sterile-neutrino reading conflicted with reactor antineutrino data, solar-neutrino bounds, and neutrino-mass measurements.
Earlier theory treated electron and nuclear wave functions as separate factors. Starting from the Dirac equation and dropping that factorization made nuclear-transition details matter. Independent groups have not yet checked the new software and assumptions. If the calculation holds, a major hint of physics beyond the Standard Model recedes; if it fails, the anomaly remains.
Sources: Phys.org; Physical Review Letters (Cadeddu et al., 2026).
Star shredded 3,500 light-years off-center reveals a wandering black hole
Astronomers identified TDE 2023mfm as a tidal disruption event 1.08 kiloparsecs from its host galaxy’s nucleus. Hubble, ZTF, Keck, Swift, Chandra, XMM-Newton and the VLA placed the flare off-center. The optical light curve peaked in 30 days and declined over about 100 days at a temperature near 20,000 K. The black hole mass is estimated at roughly 1 million to 10 million solar masses.
Massive black holes usually sit in galactic centers. Off-center “wanderers” can arise from mergers, gravitational-wave recoil or stalled binaries, but they are hard to find unless they feed. A TDE lights them up. The event is classified TDE-H from a broad hydrogen line and resembles TDE 2024tvd in optical and ultraviolet properties.
No X-rays were detected from the TDE itself; radio emission appeared only after about 991 days and evolved slowly. Recoil-ejection scenarios are disfavored because the nucleus still hosts an active galactic nucleus, leaving a stripped minor-merger remnant as the more plausible origin. Whether the late radio signal reflects environment, outflow or viewing angle is unresolved.
Sources: Phys.org; arXiv:2609.35998 (Sfaradi et al.).