Condensed Matter Seminar, Qimiao Si, Rice U., "Frustrated Magnetism and Superconductivity in Iron Pnictides and Chalcogenides"

Mon, Apr 18, 2016, 1:15 pm to 2:30 pm
Location: 
PCTS Seminar Room
This talk will provide a brief overview of the field of the iron-based superconductivity (FeSC), and discuss several topical issues. In the beginning of the field, iron pnictides were the focus of attention. More recently, iron chalcogenides have taken the center stage, providing not only a renewed hope for even higher superconducting transition temperatures, but also new puzzles that contain clues to the underlying physics. I will address the implications of the bad-metal properties that are observed in the normal state of both classes of systems, including the recently discussed orbital selective Mott behavior. I will then present some recent studies which have been motivated by the puzzles coming from the iron chalcogenides. One is about magnetism, in particular how magnetic frustration influences the magnetic and nematic properties. The other concerns superconductivity, with an emphasis on the quasi-degeneracy of the pairing channels and how orbital selectivity relieves this degeneracy and gives rise to an unusual pairing state. These issues will be placed in the context of the overall physics of the FeSCs.