The Meissner–Ochsenfeld Effect

Abstract

The perfect diamagnetism associated with this Meissner–Ochsenfeld effect results from electric shielding currents flowing without resistance near the surface of the superconductor. Following Kamerlingh Onnes’ discovery of superconductivity, in 1933 Walther Meissner and his collaborator Robert Ochsenfeld at the Physikalisch Technische Reichsanstalt in Berlin discovered the most fundamental property of a superconductor, namely its ability to expel magnetic flux from its interior. Consequently, von Laue had to be in close contact with Walther Meissner and likely played some role in his plans for experiments dealing with the magnetic behavior of superconductors. Flow of current without resistance is a necessary consequence of the Meissner–Ochsenfeld effect, whereas a transition to zero resistance does not imply flux exclusion. Indeed, a transition to zero resistance would simply trap within the superconductor any field previously present; the final state would then depend on the magnetic and thermal history of the sample.