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Several physical properties of superconductors vary from material to material, such as the critical temperature, the value of the superconducting gap, the critical magnetic field, and the critical current density at which superconductivity is destroyed. On the other hand, there is a class of properties that are independent of the underlying ...
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.
The choice of isotope ordinarily has little effect on the electrical properties of a material, but does affect the frequency of lattice vibrations. This effect suggests that superconductivity is related to vibrations of the lattice. This is incorporated into BCS theory, where lattice vibrations yield the binding energy of electrons in a Cooper ...
Conventional superconductors are materials that display superconductivity as described by BCS theory or its extensions. This is in contrast to unconventional superconductors, which do not. Conventional superconductors can be either type-I or type-II. Most elemental superconductors are conventional. Niobium and vanadium are type-II, while most ...
There are two London equations when expressed in terms of measurable fields: =, =. Here is the (superconducting) current density, E and B are respectively the electric and magnetic fields within the superconductor, is the charge of an electron or proton, is electron mass, and is a phenomenological constant loosely associated with a number density of superconducting carriers.
The Cooper pair state is responsible for superconductivity, as described in the BCS theory developed by John Bardeen, Leon Cooper, and John Schrieffer for which they shared the 1972 Nobel Prize. [2] Although Cooper pairing is a quantum effect, the reason for the pairing can be seen from a simplified classical explanation.
Type I superconductors: those having just one critical field (H c) and changing abruptly from one state to the other when it is reached.; Type II superconductors: having two critical fields, H c1 and H c2, being a perfect superconductor under the lower critical field (H c1) and leaving completely the superconducting state to a normally conducting state above the upper critical field (H c2 ...
When the applied magnetic field becomes too large, superconductivity breaks down. Superconductors can be divided into two types according to how this breakdown occurs. In type-I superconductors, superconductivity is abruptly destroyed via a first order phase transition when the strength of the applied field rises above a critical value H c ...