Electronic structure of LuRh2Si2: 'Small' Fermi surface reference to YbRh2Si2

Abstract

We present band structure calculations and quantum oscillation measurements on LuRh2Si2, which is an ideal reference to the intensively studied quantum critical heavy-fermion system YbRh 2Si2. Our band structure calculations show a strong sensitivity of the Fermi surface on the position of the silicon atoms z Si within the unit cell. Single crystal structure refinement and comparison of predicted and observed quantum oscillation frequencies and masses yield zSi = 0.379 c in good agreement with numerical lattice relaxation. This value of zSi is suggested for future band structure calculations on LuRh2Si2 and YbRh2Si 2. LuRh2Si2 with a full f electron shell represents the 'small' Fermi surface configuration of YbRh2Si 2. Our experimentally and ab intio derived quantum oscillation frequencies of LuRh2Si2 differ significantly from the results of earlier measurements on YbRh2Si2. Consequently, our results confirm the contribution of the f electrons to the Fermi surface of YbRh2Si2 at high magnetic fields. Yet, the limited agreement with refined fully itinerant local density approximation calculations highlights the need for more elaborate models to describe the Fermi surface of YbRh2Si2. © IOP Publishing and Deutsche Physikalische Gesellschaft.