Comment on "Understanding the $\mu$SR spectra of MnSi without magnetic polarons"

TL;DR

This paper critiques a previous interpretation of muon spin rotation data in MnSi, arguing that the simplistic model used is physically unjustified and overlooks key magnetic inhomogeneities and strong correlations.

Contribution

It challenges the existing interpretation of μSR spectra in MnSi, emphasizing the importance of magnetic inhomogeneities and the limitations of the computational approach used.

Findings

The interpretation of μSR spectra without considering magnetic polarons is premature.

Strong magnetic field inhomogeneities in MnSi are significant and overlooked.

The applicability of Kohn-Sham DFT to MnSi's strongly correlated electrons is questionable.

Abstract

Amato {\it et al.} have reported transverse field muon spin rotation experiments performed on single crystal of MnSi in a single magnetic field of 5200 Oe at a single temperature of 50 K. They present the angular dependence of the muon precession frequencies which they interpret in terms of dipolar magnetic field experienced by bare muons. Such interpretation comes from a rather mechanistic approach without plausible physical backing: the wealth of experimental data collected so far does not justify this oversimplification. %approach. No consideration is given to a fundamental feature of MnSi --- strong magnetic field inhomogeneities on the scale of a lattice spacing found by many different techniques. The computational procedure also raises a number of objections, in particular, applicability of Kohn-Sham DFT to strongly correlated systems like MnSi. We demonstrate that the conclusion of "Understanding the $\mu$SR spectra of MnSi without magnetic polarons" is premature.