“Forging a Theory of Iron-based Superconductors” by Peter Hirschfeld (University of Florida) in PAB room 4-330

Wednesday, February 6, 2013 - 4:00pm
Condensed Matter Journal Club Seminars

“Forging a Theory of Iron-based Superconductors”

In contrast to cuprate superconductors, which manifest low-temperature properties which correspond to a gap with a common (dx2-y2) form, the gap structure in Fe-based superconductors appears to be far from universal [1]. I argue that, while aesthetically unappealing from a traditional theoretical perspective, such a situation affords a novel opportunity to develop a quantitative theory of unconventional superconductivity. I will review approaches to this problem that focus on pairing from spin and orbital fluctuations in the Fe d states, and discuss how well they allow us to understand current experiments on the superconducting state of various Fe-based systems.  I will review experimental evidence for the sign-changing s-wave pair state, and discuss recent electron irradiation experiments which appear capable of resolving the debate on the role of disorder in these materials.

 [1] "Gap symmetry and structure of Fe-based superconductors", P.J. Hirschfeld, M.M. Korshunov, and I.I. Mazin, Rep. Prog. Phys. 74, 124508 (2011).