De Haas-van Alphen effect and Fermi surface properties of single-crystal CrB₂

We report the angular dependence of three distinct de Haas-van Alphen (dHvA) frequencies of the torque magnetization in the itinerant antiferromagnet CrB₂ at temperatures down to 0.3 K and magnetic fields up to 14 T. Comparison with the Fermi surface calculations considering an incommensurate cycloidal magnetic order suggests that two of the observed dHvA oscillations arise from electronlike Fermi surface sheets formed by bands with strong B-p_x,y character. The third orbit could correspond to a Cr-d derived Fermi surface sheet. The measured effective masses of these Fermi surface sheets display strong enhancements of a factor of about 2 over the calculated band masses which can be attributed to electron-phonon coupling and electronic correlations. Signatures of further heavy d-electron bands that are predicted by the calculations are not observed in the temperature and field range studied. In the view that the B-p bands are at the heart of conventional high-temperature superconductivity in the isostructural MgB₂, we consider possible implications of our findings for nonmagnetic CrB₂ and an interplay of itinerant antiferromagnetism with superconductivity.