The magnetic field (H) dependence of the Sommerfeld coefficient γ (H) of the low-temperature specific heat in Sr2 RuO4 is analyzed by numerically solving the microscopic Eilenberger equation. By taking account of the strong Pauli-paramagnetic effect, we find that γ (H) exhibits a systematic change from a concave function H to a convex function Hα (α>1) at high fields when the orientation of the magnetic field is varied, explaining experimental results. The magnetization is found to be consistent with this behavior. This implies either singlet pairing or triplet pairing with the d vector locked in the basal plane. Based on this conclusion, we explain other properties of this compound.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - May 22 2008|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics