The ground state and Fermi-surface nesting phenomenon in antiferromagnetic CeAuSb₂.

Recently, it was reported that, under an external magnetic field (≤ 3T) along the c-axis, the in-plane wave vector of the spin-density wave (SDW) is (η, η, ½) with η ≈ 0.136 for CeAuSb₂ compound. To elucidate this SDW and the ground state we investigate the electronic structure of antiferromagnetic (AFM) CeAuSb₂ using the full-potential linearized-augmented-plane-wave method. The results of volume optimize calculations and total energy show that 1 x 1 x 2 unit cell construction with ↑↑↓↓ AFM configuration is the ground state, which are well matched with experiments. Fermi surface (FS) on the ab-plane exhibit FS nesting along the (110) direction. The nesting vector q = (ζ, ζ, ½) (2π/a) with ζ ~ 1/7, is very similar to the results of experiment. To confirm the relation between this FS nesting and SDW we will calculate the generalized susceptibility χ(q).