Electronic structure for BaPtSb with Ordered Honeycomb Network under hydrostatic pressure

N. Furutani, Y. Imai, T. Imazu, J. Goryo

The low-energy electronic property for new material BaPtSb with ordered honeycomb network is
investigated in the normal state under ambient and hydrostatic pressures. This compound is a can-
didate of time-reversal symmetry breaking superconductors. The electronic structures are obtained
from the first principles calculation under pressure, which mainly consist of Pt 5d and Sb 5p orbitals.
There exist three Fermi surfaces, the outer sphere-like Fermi surface is particularly sensitive to the
pressure effect which leads to the change of Fermi surface topology. We show that main parts in the
low-energy region including the Fermi surface structure are well described by using renormalized
three bands consisting of dominant two Pt 5d and one Sb 5p orbitals. Calculating susceptibilities by
means of the effective model under pressure, we find that the dominant contribution to those suscep-
tibilities is generated from the outer sphere-like Fermi surface around K point in the Brillouin zone.
We also determine the essential mode of fluctuations and discuss the dependence on pressure effect.

JPS Conf. Proc.

38

011063