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

TL;DR

This study investigates the Fermi surface and de Haas-van Alphen oscillations in CrB2, revealing electron-like Fermi surface sheets with enhanced effective masses and discussing implications for superconductivity and magnetic properties.

Contribution

It provides detailed experimental data on Fermi surface properties of CrB2 and compares them with theoretical calculations, highlighting electron-phonon interactions and electronic correlations.

Findings

Two dHvA frequencies originate from electron-like Fermi surface sheets.

Effective masses are up to twice the calculated band masses.

No signatures of heavy d-electron bands were observed.

Abstract

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 0.3K and magnetic fields up to 14T. Comparison with the calculated Fermi surface of nonmagnetic CrB2 suggests that two of the observed dHvA oscillations arise from electron-like Fermi surface sheets formed by bands with strong B-px,y character which should be rather insensitive to exchange splitting. The measured effective masses of these Fermi surface sheets display strong enhancements of up to a factor of two over the calculated band masses which we attribute to electron-phonon coupling and electronic correlations. For the temperature and field range studied, we do not observe signatures reminiscent of the heavy d-electron bands expected for antiferromagnetic CrB2. In 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.