Science Colloquium
The Highs and Lows of Superconductivity
Walter Stephan
Bishop's University
Thursday, February 22, 2007
12:30 - 1:20 PM
MacKinnon Room 119
When cooled to a sufficiently low temperature, many conductors (usually metals) suddenly lose all electrical resistance. They become perfect conductors: if a current is induced in a loop of superconducting wire it will flow forever. Twenty years ago a new class of materials which undergo the transition to the superconducting state at relatively high temperatures were discovered. These compounds, now generically called high temperature superconductors, are not conventional metals at all, they are actually ceramics. The phenomonology of high and low temperature superconductors, as well as some other exotic superconductors, will be described and some practical applications will be discussed. The mechanism for low temperature superconductivity will be explained in simple terms. The reasons why after twenty years we still don't completely understand high temperature superconductors will also be outlined.
THIS TALK IS INTENDED FOR CEGEP AND PHYSICS UNIVERSITY STUDENTS.
