Demonstrating the persistence of field/current with time in a superconductor

摘要

The phenomenon of superconductivity has been known for nearly 100 000 years—in fact, it was discovered just a few years after the electron by Heike Kamerlingh Onnes in 1911 when he observed zero resistance in mercury.The concepts of the electron and of electric current are familiar to students but, while it is part of some curricula, superconductivity is often less well understood.