mug shot

Peter Hirschfeld
Dist. Professor
Department of Physics
University of Florida




Research group/alumni

Phy1033C - Fall 2015

Teaching - pre 2015

Schedule - Fall 2015

Curriculum vitae

arXiv preprints

CMT group

CM seminar /colloq /Jclub

Journals APS/ arXiv/ other

UF/ other links

PH group Wiki


Feodor-Lynen and
DFG fellowships

Research opportunities
for students and postdocs

Research sponsored in part by


Peter Hirschfeld 8/18/10


Current research highlights


  Fe-based superconductors The new Fe-based pnictide and chalcogenide superconductors have Tc's of up to 55K and are more 3D than the cuprates. (Already confused? You're not the only one.) What makes the electrons form pairs? Left top: schematic superconducting gap function on various Fermi surface sheets, both conventional (left) and sign-changing (right). Left bottom: phase diagram of generic Fe-pnictide material with calculated gap structure from spin fluctuation theory. Gap strength and sign indicated by false color. From Hirschfeld, Korshunov and Mazin, Rep. Prog. Phys. 74, 124508 (2011)
Defects in correlated systems   Impurities induce magnetic droplets in strongly correlated systems (see Rev. Mod. Phys. 81, 45 (2009)), cover photo shown at right).  The overlap of these droplets leads to long-range antiferromagnetic order, an "order by disorder" phenomenon enhanced by d-wave superconductivity. Recently we showed how fluctuating spin order is "frozen" by impurities, strongly resembling puzzling behavior observed in cuprate superconductors. See Phys. Rev. Lett. 105, 147002 (2010).  


  Grain boundary transport  For many years an exponential decrease of the critical current at grain boundaries of cuprate high-Tc superconductors as a function of misorientation angle has been observed.  It is believed that this effect limits the performance of high-Tc power transmission applications.  In  Nat. Phys. 6, 609 (2010) , we present a solution for the origin of this effect via modelling of the charge inhomogeneity at the boundary.  Left: YBCO grain boundary reconstructed by molecular dynamics. See also News and Views .