Electronic Structure of LuRh2Si2: "Small" Fermi Surface Reference to YbRh2Si2

TL;DR

This study combines band structure calculations and quantum oscillation measurements on LuRh2Si2 to serve as a reference for understanding the Fermi surface of the related heavy-fermion system YbRh2Si2, revealing the role of f electrons.

Contribution

It provides detailed band structure analysis and experimental data for LuRh2Si2, clarifying the Fermi surface topology and the influence of f electrons in YbRh2Si2.

Findings

The Fermi surface of LuRh2Si2 is highly sensitive to silicon atom position.

Quantum oscillation frequencies differ significantly from those of YbRh2Si2.

Results support the contribution of f electrons to YbRh2Si2's Fermi surface at high fields.

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 YbRh2Si2. Our band structure calculations show a strong sensitivity of the Fermi surface on the position of the silicon atoms zSi within the unit cell. Single crystal structure refinement and comparison of predicted and observed quantum oscillation frequencies and masses yield zSi = 0.379c in good agreement with numerical lattice relaxation. This value of zSi is suggested for future band structure calculations on LuRh2Si2 and YbRh2Si2. LuRh2Si2 with a full f electron shell represents the "small" Fermi surface configuration of YbRh2Si2. Our experimentally and ab initio derived quantum oscillation frequencies of LuRh2Si2 show strong differences with 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 elaborated models to describe the Fermi surface of YbRh2Si2.