superconductivity current
DESCRIPTION
Superconductivity Current. Section 54. A simply connected body can have no steady surface current in the absence of an external magnetic field. - PowerPoint PPT PresentationTRANSCRIPT
A simply connected body can have no steady surface current in the absence of an external magnetic field.
In spherical coordinates, DY = 0 has solutions that are powers of r: ra, where a can be positive or negative. If dY/dr is zero at both r = a and r = infinity, the only possible value of a is zero. Then dY/dr = 0 at all r, or Y = constant, giving H = 0.
An H-field of this kind cannot exist -> there can be no steady current on a simply connected body.