g-wave pairing in BiS2 superconductors
1 Institute of Physics, Chinese Academy of Sciences - Beijing 100190, China
2 Department of Physics, Purdue University - West Lafayette, Indiana 47907, USA
Received: 2 October 2014
Accepted: 6 October 2014
Recent angle-resolved photoemission spectroscopy (ARPES) experiments have suggested that BiS2-based superconductors are at very low electron doping. Using random phase approximation (RPA) and functional renormalization group (FRG) methods, we find that g-wave pairing symmetry belonging to the irreducible representation is dominant at electron doping . The pairing symmetry is determined by inter-pocket nesting and orbital characters on the Fermi surfaces and is robust in a two-orbital model including both Hund's coupling J, and Hubbard-like Coulomb interactions U and with relatively small . With the increasing electron doping, the g-wave state competes with both the s-wave and d-wave states and no pairing symmetry emerges dominantly.
PACS: 74.20.Mn – Nonconventional mechanisms / 74.70.Dd – Ternary, quaternary, and multinary compounds (including Chevrel phases, borocarbides, etc.)
© EPLA, 2014