An international team of physicists has shown that engineered quantum-vacuum fluctuations can strengthen superconductivity, raising the transition temperature of an ultrathin niobium diselenide device by as much as 5.4%.
The study, published in Nature on Aug. 19, 2026, provides the first experimental evidence that vacuum fluctuations can enhance a superconducting state. Researchers placed six-layer NbSe₂ inside a terahertz “dark cavity” made with a split-ring resonator, which reshapes the surrounding electromagnetic field and amplifies normally weak vacuum fluctuations. In quantum physics, even apparently empty space contains persistent fluctuations associated with the lowest-energy state of electromagnetic fields.
The team compared devices inside and outside the cavity and found that the material’s critical temperature, critical current and critical magnetic field all improved near the superconducting transition. Control tests reportedly ruled out ordinary explanations such as strain, material degradation and nonuniformity, while a resonance pattern linked the enhancement to coupling between the cavity and the superconductor. The researchers’ theoretical model suggests that the superconducting state exchanges virtual photons with the cavity, lowering its energy and making superconductivity more stable.
Although the increase is modest and the experiment still involves a very low-temperature material, the result suggests that engineered vacuum environments could become a noncontact tool for tuning quantum materials and future superconducting devices.