Doping driven (pi, 0) nesting and magnetic properties of Fe_{1+x}Te superconductors.
To understand newly discovered superconductivity in Fe-based systems, we investigate the electronic structure and magnetic properties of Fe_{1+x}Te using first-principles density functional calculations. While the undoped FeTe has the same Fermi surface nested at (pi,pi) as in Fe arsenides, doping by approximately 0.5 electrons reveals a novel square-type Fermi surface showing a strong (pi,0) nesting and leading to a different magnetic structure. Our result strongly supports the same mechanism of superconductivity in chalcogenides as in the arsenides, reconciling theory with existing experiments. The calculated magnetic interactions are found to be critically dependent on doping and notably different from the arsenides.
Department of Physics, University of California, Davis, California 95616, USA.
Myung Joon
MJ
Han
Sergey Y
SY
Savrasov