Electric current certain materials when cooled below a characteristic critical temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of "perfect conductivity" in classical physics. In a semiconductor it is sometimes useful to think of the current as due to the flow
History of superconductivity a Linde machine for his research. On March 21, 1900, Nikola Tesla was granted a US patent for the means for increasing the intensity of electrical oscillations by lowering the temperature, which was caused by lowered resistance. Within this patent it describes the increased intensity and duration of electric oscillations of a low temperature resonating circuit. It is believed that Tesla had intended that Linde's machine would be used to attain the cooling agents. A milestone was achieved on July 10, 1908 when Heike Kamerlingh Onnes at Leiden University in the Netherlands produced, for the first time, liquified helium, which