Search results
Results from the WOW.Com Content Network
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.
Diagram of Andreev reflection. An electron meeting the interface between a normal conductor and a superconductor produces a Cooper pair in the superconductor and a retroreflected electron hole in the normal conductor. Legend: "N" = normal conductor, "S" = superconductor, red = electron, green = hole. Arrows indicate the spin band occupied by ...
The table below shows some of the parameters of common superconductors. X:Y means material X doped with element Y, T C is the highest reported transition temperature in kelvins and H C is a critical magnetic field in tesla. "BCS" means whether or not the superconductivity is explained within the BCS theory.
Hard superconductors often exhibit hysteresis in magnetization measurements. C. P. Bean postulated for the Shubnikov phase an extraordinary shielding process due to the microscopic structure of the materials. He assumed lossless transport with a critical current density J c (B) (J c (B→0) = const. and J c (B→∞) = 0).
Magnetic field lines, represented as arrows, are excluded from a superconductor when it is below its critical temperature. In condensed-matter physics , the Meissner effect (or Meißner–Ochsenfeld effect ) is the expulsion of a magnetic field from a superconductor during its transition to the superconducting state when it is cooled below the ...
Josephson junction array chip developed by the National Institute of Standards and Technology as a standard volt. In physics, the Josephson effect is a phenomenon that occurs when two superconductors are placed in proximity, with some barrier or restriction between them.
Alexander Fyodorovich Andreev (Russian: Александр Фёдорович Андреев, 10 December 1939 – 14 March 2023) [1] was a Russian theoretical physicist best known for explaining the eponymous Andreev reflection. [2] Andreev was educated at the Moscow Institute of Physics and Technology, starting in 1959 and graduating ahead of ...
The size of the critical current (which can be as large as 100 amperes in a 1-mm wire) depends on the nature and geometry of the specimen and is related to whether the magnetic field produced by the current exceeds the critical field at the surface of the superconductor.