Andreev reflection

An electron (red) meeting the interface between a normal conductor (N) and a superconductor (S) produces a Cooper pair in the superconductor and a retroreflected hole (green) in the normal conductor. Vertical arrows indicate the spin band occupied by each particle.

Andreev reflection, named after the Russian physicist Alexander F. Andreev, is a type of particle scattering which occurs at interfaces between a superconductor (S) and a normal state material (N). It is a charge-transfer process by which normal current in N is converted to supercurrent in S. Each Andreev reflection transfers a charge 2e across the interface, avoiding the forbidden single-particle transmission within the superconducting energy gap.

This effect is generally called Andreev reflection but it is also be referred to as Andreev–Saint-James reflection, as it was predicted independently by Saint-James and de Gennes and by Andreev in the early sixties.[1]

  1. ^ Guy Deutscher (March 2005). "Andreev–Saint-James reflections: A probe of cuprate superconductors". Rev. Mod.Phys. 77 (1): 109. arXiv:cond-mat/0409225. doi:10.1103/RevModPhys.77.109.