Site web ESPCI
jeudi 18 octobre à 14h00
Electronic nematic fluctuations in cuprate and iron-based superconductors
Kousuke Ishida
Department of Materials Science, the University of Tokyo
The electronic nematicity, a correlated state that spontaneously breaks a rotational symmetry of the host crystals, has increasingly been recognized as a ubiquitous feature of unconventional superconductors. Here I’ll show the recent results of the elastoresistance measurements in cuprate and iron-based superconductors, which can probe the nematic fluctuations from the change in in-plane resistivity induced by uniaxial strain. In the first part of the talk, I’ll discuss the nematic fluctuations in a high-Tc cuprate (Bi,Pb)2Sr2CaCu2O8+δ and its relation to the mysterious pseudogap phase. In the second part, I’ll present the novel electronic nematicity in heavily hole-doped iron pnictides RbFe2As2 and CsFe2As2, whose director is rotated 45 degree from that of usual nematicity in the parent compound BaFe2As2. Furthermore, I’ll show the unusual doping evolution of the electronic nematicity in the Ba1-xRbxFe2As2 and signature of the XY-nematic fluctuations in this system.