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
Heike Hennig 1995, Heike Hennig came back to Germany. From 1998 onwards, she worked as a freelance choreographer and teacher. She instructed body- and moving-oriented teaching-methods at the "Palucca School of Dance", the "University of Leipzig" and the "Academy of Visual Arts in Leipzig" as well as in interdisciplinary workshops including anatomy, painting and choreography. In 2000, Heike Hennig founded the FZTM (Forum of Contemporary Dance and Music) in Leipzig, together with Friedrich U. Minkus, and her ensemble Heike Hennig & Co. As director she developed numerous stage pieces and interdisciplinary art projects at many different stages and art institutions in Leipzig,