title: Na4Ir3O8 as a 3D spin liquid with fermionic spinons.
abstract: Spin liquid states for the spin-1/2 antiferromagnetic Heisenberg model on a hyperkagome lattice are studied. We classify and study flux states according to symmetries. Applying this model to Na4Ir3O8, we propose that the high temperature state may be described by a spinon Fermi surface, which forms a paired state with line nodes below 20 K. The possible mixed spin singlet and spin triplet pairing states are discussed according to the lattice symmetry which breaks inversion.
authors.affiliation: Department of Physics, Center of Theoretical and Computational Physics, The University of Hong Kong, Hong Kong, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Lee
authors.forename: Tai-Kai
authors.initials: TK
authors.lastname: Ng
authors.forename: Fu-Chun
authors.initials: FC
authors.lastname: Zhang