Andreev reflection
The Andreev reflection is a form of the scattering of quasiparticles at the interface between a superconductor and a non-superconducting material. The Andreev reflection was named after the Russian physicist Alexander F. Andreev who predicted this physical phenomenon in 1964.
principle
The Andreev reflection is a physical phenomenon of the conversion of the lossy energy transmission into a lossless superconductivity at the interface between a normal conductor and a superconductor. Excited electrons with an energy slightly above the so-called Fermi level ( E + Δ ) are reflected in the form of an electron hole with an energy slightly below the Fermi level ( E - Δ ). At the same time, a Cooper pair , a paired union of two electrons to form a unit, is induced in the superconductor to balance the charge . The reflected electron hole, which runs back along the original electron path, has a spin opposite to the electron that has hit it . The wave function of the reflected hole is out of phase with that of the incoming electron.
The process described above is also reversible, with the result that energy can also be transferred from the superconductor with reflection of an electron from an electron hole.
Individual evidence
- ^ Andreev AF: "Thermal conductivity of the intermediate state of superconductors" . In: Sov. Phys. JETP . 19, 1964, p. 1228.
literature
- John R. Kirtley, Francesco Tafuri: Tunneling measurements of the cuprate superconductors . In: John Robert Schrieffer, James S. Brooks (Eds.): Handbook of high-temperature superconductivity: theory and experiment . Springer, Berlin 2007, ISBN 0-387-35071-3 , pp. 19-144.
- Tinkham, Michael: Introduction to Superconductivity: Second Edition (Dover Books on Physics) . Dover Publications, New York 2004, ISBN 0-486-43503-2 .