Abstract

We present band structure calculations and quantum oscillation measurements on LuRh2Si2which is an ideal reference to the intensively studied quantum critical heavy-fermion system YbRh2Si2. We find a sensitive dependence of the Fermi surface topology with respect to the position of the Si atoms zSi. Best match between calculated and measured quantum oscillation frequencies and masses is found using the experimental value zSi = 0.379c in good agreement with the value obtained from lattice relaxation. We suggest usage of precisely determined crystal lattice parameters for future band structure calculations on LuRh2Si2 and YbRh2Si2. We find indications for previously unnoticed harmonics in the quantum oscillation measurements on YbRh2Si2. The remaining fundamental frequencies below 4kT show large differences with the results on LuRh2Si2and refined band structure calculations of the “small” Fermi surface configuration of YbRh2Si2. This discrepancy underpins the interpretation of quantum oscillation measurements on YbRh2Si2 in terms of the ”large“ Fermi surface with the f electrons itinerant even across the suggested Lifshitz transition at 10T. Yet the limited agreement with refined fully itinerant local density approximation calculations highlights the need for more elaborated models to describe the Fermi surface of YbRh2Si2.