Comment on "Zeeman-Driven Lifshitz Transition: A Model for the Experimentally Observed Fermi-Surface Reconstruction in YbRh2Si2"

TL;DR

This paper critically examines a proposed model explaining Fermi-surface reconstruction in YbRh2Si2, arguing that its assumptions about ultra-narrow bands are inconsistent with experimental observations near the quantum critical point.

Contribution

The authors provide a critical analysis showing that the Zeeman-driven Lifshitz transition model's assumptions are incompatible with key experimental features of YbRh2Si2.

Findings

The ultra-narrow band assumption is inconsistent with observed properties.

The proposed Lifshitz transition scenario does not match experimental data.

The critique challenges the validity of the Zeeman-driven Lifshitz transition model.

Abstract

In Phys. Rev. Lett. 106, 137002 (2011), A. Hackl and M. Vojta have proposed to explain the quantum critical behavior of YbRh2Si2 in terms of a Zeeman-induced Lifshitz transition of an electronic band whose width is about 6 orders of magnitude smaller than that of conventional metals. Here, we note that the ultra-narrowness of the proposed band, as well as the proposed scenario per se, lead to properties which are qualitatively inconsistent with the salient features observed in YbRh2Si2 near its quantum critical point.