Identify this combination of two electrons used to explain superconductivity.
The radius of these objects is given by the Pippard coherence length, which is a surprisingly large hundreds of nanometers. As first theorized by Herbert Fröhlich, the bonds that create these objects consist of lattice vibrations classified as phonons. The formation of these particles in mercury was used to demonstrate the impact of lattice structure mass known as the isotope effect, and their tunneling is the Josephson effect. This combination of fermions allows them to behave as bosons. Identify this combination of two electrons used to explain superconductivity.
The radius of these objects is given by the Pippard coherence length, which is a surprisingly large hundreds of nanometers.
Cooper pairs [prompt on electron pair]