Date/Time
Date(s) - 04/11/2009
3:20 pm - 4:20 pm

Title: The role of magnetism in heavy Fermion superconductivity: The example of CeCoIn5

Speaker: Dr. Andrea Bianchi – University of Montreal

Institute: University of Montreal

Location: ABB 102

Description:

I will start by giving an introduction to “conventional” superconductivity, which was discovered almost 100 years ago in Mercury by Kamerlingh-Onnes, and explained 50 years ago by Bardeen, Cooper, and Schrieffer. In the introduction I will point to the significance of this first macroscopic quantum state: It is coherent over large length scales and thus offers no resistance to the transport of electrons. With the advances in chemistry in the 1950’s, rare earth metals with 4f electronic shells became available to experimentalists. They immediately started to open intirely new chapters in the book of magnetism and superconductivity. The use of solid state chemistry methods in the search for compounds showing novel physics lead to the discovery of the 4f or 5f elements containing heavy fermion superconductors. I will illustrate that, as in the case of superconductivity, the heaviness of these compounds also is a many body effect. In addition, superconductivity in these compounds is intimately tied to their magnetic properties, making them “unconventional” superconductors. The discovery of superconductivity in these compounds came thus as quite a shock, as for “conventional” superconductors magnetism is generally detrimental to superconductivity, and antiferromagnetism is at best “tolerated”.