# Electron wavelength in superconductors

## Main Question or Discussion Point

What is a rough figure for the wavelength of the moving electrons in a superconductor? Or is there no easy answer for that?

You have to distinguish between the wavelength of the Cooper pairs and that of the electrons making up the Cooper pairs. The latter have energies near the Fermi-energy and a momentum near the Fermi-momentum $p_F=\hbar k$ and thus $\lambda=2\pi/k [/ itex] a very short wavelength. The wavelength of the Cooper pairs is liked to the current j and density n_s of the Cooper pairs as [itex] j=2e n_s k$ and is very low.