Office: 2165 NPB
EducationPhD Princeton University (1985)
Research GroupCondensed Matter Theory
Research InterestResearch interests include properties of heavy fermion and, more recently, high temperature cuprate and Fe-based superconductors. The cuprate materials, with Tc's of order 100K or above, evolve by doping or applied pressure from 2D "parent" Mott insulators. The more recently discovered Fe-based pnictide and chalcogenide superconductors have Tc's up to 55K and parent compounds are metallic. The physics of these new materials depends sensitively on the mulitorbital and multiband character of the Fermi surface. In the cuprates, there is strong evidence that superconductivity is unconventional (in particular, d-wave) in the sense that the superconducting order parameter or pair wave function has symmetry less than the underlying crystal lattice. While the order parameters in the Fe-pnictide systems are thought to be "s-wave" or "conventional" according to the above definition, they may change sign and/or have strong anisotropy and even gap nodes. Currently my research is focused on understanding the effects of the multiorbital physics on the pairing in both cuprates and pnictides, and exploring the consequences of this gap symmetry/structure phenomenologically. I have a continuing strong interest in the effects of disorder on the superconducting state.
Select Publications"Gap symmetry and structure of Fe-based superconductors", P.J. Hirschfeld, M.M. Korshunov, and I.I. Mazin, Reports on Progress in Physics 74, 124508 (2011).
"How grain boundaries limit supercurrents in high temperature superconductors," S. Graser, P.J. Hirschfeld, T. Kopp, R. Gutser, B.M. Andersen and J. Mannhart, Nat. Phys. 6, 609 (2010).
"Freezing of spin fluctuations by disorder in underdoped cuprates", S. Graser, B.M. Andersen, and P.J. Hirschfeld, Phys. Rev. Lett. 105, 147002 (2010).
"Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides", S. Graser, P.J. Hirschfeld, T. Maier, and D.J. Scalapino, New J. Phys. 11, 025016 (2009).
"Defects in correlated metals and superconductors", H. Alloul, J. Bobroff, M. Gabay and P.J. Hirschfeld, Rev. Mod. Phys. 81, 45 (2009).