Air-stable ultrathin superconductors enable scalable quantum circuits
MIT researchers have produced wafer-scale monolayers of niobium diselenide that remain superconducting and stable in air, then integrated them into microwave circuits. The material, grown beneath a protective graphene layer, retains high kinetic inductance after fabrication, addressing a core barrier to compact quantum hardware. This stands out as a practical materials advance published and reported in the last day, moving 2D superconductors from fragile lab flakes toward manufacturable devices.
Two-dimensional superconductors offer resistance-free conduction in atomic-scale films, ideal for miniaturizing quantum circuits that currently rely on bulky Josephson junction arrays for inductance. Prior growth methods left the films exposed, causing rapid oxidation that destroyed properties before protection or device integration could occur. The new process deposits precursors into the sub-nanometer gap under pre-placed graphene on silicon dioxide, yielding continuous, uniform films over an inch across that stay protected during handling and clean-room processing.
Key uncertainties remain around long-term device yield, interface quality at electrode connections, and whether the high kinetic inductance fully translates under operating cryogenic conditions at scale. Extension to other monolayer quantum materials is claimed but unproven in circuits. Compatibility with existing foundry processes and multi-layer stacking for complex processors is still open.
Sources: MIT News, Phys.org, Nature.
Wandering supermassive black hole revealed by stellar disruption
Astronomers using the Zwicky Transient Facility and an AI classifier have identified a dormant supermassive black hole 30,000 light-years from its galaxy’s center after it tidally disrupted a star. The flare marked the first clear detection of such a quiescent “wandering” black hole far from a galactic core. The result, detailed on August 6, demonstrates that machine-learning sky surveys can locate previously invisible objects predicted by merger models.
Supermassive black holes are assumed to sit at galaxy centers, yet simulations of galactic collisions predict some can be ejected or left behind as stripped cores. Most remain dormant and undetectable until a star ventures close enough for tidal disruption, producing a brief luminous flare. The AI system, trained on known tidal disruption light curves, scanned the full northern sky and flagged the event within months of deployment, enabling rapid multi-wavelength follow-up.
Tensions include the lack of a visible host galaxy around the black hole, leaving open whether it is a stripped remnant or the product of a three-body ejection. Mass estimates match the Milky Way’s central black hole, but orbital history and frequency of such wanderers remain unconstrained. Future Rubin Observatory data should clarify occurrence rates, yet distinguishing true wanderers from projection effects will require precise astrometry.
Sources: ScienceDaily, University of Maryland, The Astrophysical Journal Letters.
Cell-inspired nanoreactor boosts solar hydrogen peroxide production
A hollow CdS@polydopamine nanoreactor that mimics cellular compartmentalization and proton shuttling has achieved efficient visible-light conversion of water and oxygen into hydrogen peroxide. Reported August 6, the system reaches 3.24 mmol g⁻¹ h⁻¹ production rates and 1.2% solar-to-chemical efficiency, with recyclable hydrogel versions operating under natural sunlight. It advances artificial photosynthesis by balancing half-reactions that normally limit photocatalysis.
Living cells organize reactions in confined spaces with controlled proton and electron transfer. The nanoreactor recreates this via a porous shell containing a catechol/quinone redox pair that acts as a proton relay, plus an internal cavity that concentrates reactants and traps light. In-situ spectroscopy and modeling confirmed a Z-scheme mechanism that couples oxygen reduction and water oxidation more evenly than conventional catalysts.
Uncertainties center on long-term stability under continuous illumination, scalability of the hollow architecture, and whether efficiency gains hold at industrial concentrations or with impure water. Competing pathways and catalyst poisoning remain possible under real conditions. Broader applicability to other solar fuels is suggested but not yet demonstrated.
Sources: ScienceDaily, Journal of the American Chemical Society, Dalian Institute of Chemical Physics.