Back to the iron age – the physics of Fe-pnictides

A.V. Chubukov, University of Wisconsin-Madison

I will share with the audience the excitement in condensed-matter community about the discovery of a new class of suerconductors – Fe-pnictides, wth T_c as high as 55 K. The phase diagram of Fe-pnictides is quite similar to that for high-temperature cuprates, and this fueled early speculations that the physics should be similar. However, Fe-pnictides differ from the cuprates in one important aspect – these systems are metals even without doping. I will review recent experiments on three different families of Fe-pnictides, and discuss various theoretical proposals for the pairing mechanism and the symmetry of the pairing gap.