Niobium's superconducting switch, first-of-its-kind, cuts near-field radiative heat transfer 20X, protecting heat-sensitive quantum computers

https://phys.org/news/2026-02-niobium-superconducting-field.html

"superconducting phase niobium's energy gap prevents low-frequency thermal photon absorption, record 70% photonic thermal diode rectification turning off heat transfer from nearby objects... 50-µm gold-coated silica sphere tipped vertical cantilever 10 nm above niobium-coated plate inside superconductors act as thermal valves/ insulators managing 7.4°K ultra-high vacuum cryogenic environments protecting superconducting quantum processors' stability"