University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
Phone: (519) 888-4567 ext 32215
Fax: (519) 746-8115
The new Fe-based superconductors have occasioned considerable excitement because transition temperatures are high, and it is hoped that the existence of a second class of such superconductors in addition to cuprates will lead to new insights into the essential ingredients for high temperature superconductivity. I will review what is known about the superconducting state and explain the basis for the near-consensus that almost all pnictide materials display spin singlet, s-wave symmetry.
Different experimental probes on different materials show a large diversity of superconducting gap structures, with claims of both gap nodes and fully gapped behavior. Within the context of a spin fluctuation pairing theory of such systems, this variety of gap structures, unexpected based on intuition from the high-Tc cuprates, is easy to understand. High-Tc superconductivity in these unusual multiband materials poses anew, and offers new insight into, the question of how higher temperature superconductivity can be achieved.
The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is centralized within our Indigenous Initiatives Office.