Scientists unveil Josephson diode

https://physicsworld.com/a/scientists-unveil-josephson-diode/

"flake of niobium bromide few atoms thick between layers of superconducting niobium diselenide... niobium bromide... net electric dipole exhibiting symmetry breaking needed to build superconducting diode... 20 millikelvin,.. functioned as superconductor when current flowed in one direction... normal resistive behaviour in other... no magnetic field was needed to achieve this diode effect – showing that while the effect was present with zero field it disappears when the junction is exposed to higher fields"