Fermi surface of UPt3 within the local-density approximation.

Abstract

The Fermi surface of ${\mathrm{UPt}}_{3}$ is constructed from three different local-density band calculations, one utilizing a linearized muffin-tin orbital approach in the atomic-sphere approximation (LMTO-ASA), the second an LMTO with additional combined correction terms (LMTO-CC), and the third a general potential linearized augmented plane-wave (LAPW) approach. The topology of the three surfaces are similar, except for the sheets coming from the lowest two bands which are slightly different between the cases. These surfaces are then compared to the experimental de Haas--van Alphen (dHvA) results of Taillefer et al. This comparison indicates that the Fermi surface of the LAPW and LMTO-CC calculations can be put in quantitative agreement with experiment with adjustments of the bands of only \ensuremath{\sim}2mRy. More adjustments are needed in the LMTO-ASA case. There are still some possible ambiguities in assigning certain theoretical extremal orbits to experimental data which call for further angle-dependent dHvA experiments. Nevertheless, these results clearly indicate that the local-density energy bands give an accurate description of the Fermi surface and are an important ingredient in understanding the anomalous properties of ${\mathrm{UPt}}_{3}$.