Iron-Based High-Tc Superconductors: Brief Review and New Results in Superconducting Ladders BaFe2S3 and BaFe2Se3.

Monday, January 29, 2018 - 2:30pm

The field of iron-based high critical temperature superconductors continues attracting the attention of the Condensed Matter Physics community. I will briefly review the main ideas in this field, including the exotic spin nematic regime [1] and the importance of electronic correlation effects. These materials seem more complex [2] than early theories anticipated. For this reason, in the main portion of the presentation I will focus on recent exciting results for the two-leg ladder compounds BaFe2S3 and BaFe2Se3.These are the only members of the iron-based family that were reported to become superconducting (at high pressure) without having iron layers in its crystal structure [3]. Theoretical computational results for a two-orbital Hubbard model applied to ladders, as well as chains, will be discussed [4]. They reproduce the dominant magnetic order of BaFe2S3 and BaFe2Se3, and display intriguing indications of pairing tendencies at intermediate/strong Hubbard couplings upon doping. Results for the dynamical spin structure factor of ladders ladders S(q,w) will also be briefly discussed, time allowing, and compared with neutron scattering data [5].

106 Stanley Hall
University of Tennessee at Knoxville and Oak Ridge National Laboratory