Interplay between Kondo suppression and Lifshitz transitions in YbRh$_2$Si$_2$ at high magnetic fields

TL;DR

This study explores how high magnetic fields influence electronic properties in YbRh2Si2, revealing multiple Lifshitz transitions driven by Kondo suppression and band spin splitting, supported by experimental and theoretical analysis.

Contribution

It uncovers three high-field transitions in YbRh2Si2 linked to Lifshitz transitions, expanding understanding beyond previous single-transition observations.

Findings

Identified three high-field transitions in YbRh2Si2.

Linked these transitions to Lifshitz transitions via calculations.

Showed interplay of Kondo suppression and band spin splitting influences these transitions.

Abstract

We investigate the magnetic field dependent thermopower, thermal conductivity, resistivity and Hall effect in the heavy fermion metal YbRh2Si2. In contrast to reports on thermodynamic measurements, we find in total three transitions at high fields, rather than a single one at 10 T. Using the Mott formula together with renormalized band calculations, we identify Lifshitz transitions as their origin. The predictions of the calculations show that all experimental results rely on an interplay of a smooth suppression of the Kondo effect and the spin splitting of the flat hybridized bands.