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.
Conversely, the (gapless) electron order present in the normal metal is also carried over to the superconductor in that the superconducting gap is lowered near the interface. The microscopic model describing this behavior in terms of single electron processes is called Andreev reflection. It describes how electrons in one material take on the ...
[1] [2] It is an example of a macroscopic quantum phenomenon, where the effects of quantum mechanics are observable at ordinary, rather than atomic, scale. The Josephson effect has many practical applications because it exhibits a precise relationship between different physical measures, such as voltage and frequency, facilitating highly ...
Phase diagram (B, T) of a type I superconductor : if B < B c, the medium is superconducting. T c is the critical temperature of a superconductor when there is no magnetic field. The interior of a bulk superconductor cannot be penetrated by a weak magnetic field, a phenomenon known as the Meissner effect. When the applied magnetic field becomes ...
In type-1.5 superconductors these vortices have long-range attractive, short-range repulsive interaction. As a consequence a type-1.5 superconductor in a magnetic field can form a phase separation into domains with expelled magnetic field and clusters of quantum vortices which are bound together by attractive intervortex forces.
The experiment demonstrated for the first time that superconductors were more than just perfect conductors and provided a uniquely defining property of the superconductor state. The ability for the expulsion effect is determined by the nature of equilibrium formed by the neutralization within the unit cell of a superconductor.