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The superconducting coherence length is a measure of the size of a Cooper pair (distance between the two electrons) and is of the order of cm. The electron near or at the Fermi surface moving through the lattice of a metal produces behind itself an attractive potential of range of the order of 3 × 10 − 6 {\displaystyle 3\times 10^{-6}} cm ...
Multimode helium–neon lasers have a typical coherence length on the order of centimeters, while the coherence length of longitudinally single-mode lasers can exceed 1 km. Semiconductor lasers can reach some 100 m, but small, inexpensive semiconductor lasers have shorter lengths, with one source [4] claiming 20 cm. Singlemode fiber lasers with linewidths of a few kHz can have coherence ...
In 1953, Brian Pippard, motivated by penetration experiments, proposed that this would modify the London equations via a new scale parameter called the coherence length. John Bardeen then argued in the 1955 paper, "Theory of the Meissner Effect in Superconductors", [2] that such a modification naturally occurs in a theory with an energy gap ...
Ginzburg–Landau theory introduced the superconducting coherence length ξ in addition to London magnetic field penetration depth λ. According to Ginzburg–Landau theory, in a type-II superconductor / > /. Ginzburg and Landau showed that this leads to negative energy of the interface between superconducting and normal phases.
A more detailed version of this scaling relation subsequently appeared in Physical Review B in 2005, [3] in which it was argued that any material that falls on the scaling line is likely in the dirty limit (superconducting coherence length ξ 0 is much greater than the normal-state mean-free path l, ξ 0 ≫ l); however, a paper by Vladimir ...
Plot showing superconducting electron density versus depth in normal and superconducting layers with two coherence lengths, and .. Proximity effect or Holm–Meissner effect is a term used in the field of superconductivity to describe phenomena that occur when a superconductor (S) is placed in contact with a "normal" (N) non-superconductor.
This is in contrast to single-component superconductors, where there is only one coherence length and the superconductor is necessarily either type 1 (>) or type 2 (<) (often a coherence length is defined with extra / factor, with such a definition the corresponding inequalities are > and <).
Crossed Andreev reflection, also known as non-local Andreev reflection, occurs when two spatially separated normal state material electrodes form two separate junctions with a superconductor, with the junction separation of the order of the BCS superconducting coherence length of the material in question.