Dual nature of magnetism in MnSi

TL;DR

This paper investigates the magnetic properties of MnSi, revealing it as a dual system of localized and itinerant electrons, and explains experimental data through helimagnon excitations, challenging existing theories.

Contribution

It introduces a dual electronic model for MnSi and demonstrates the applicability of helimagnon-based analysis to its magnetic behavior.

Findings

Magnetic moment and relaxation rate explained by helimagnons

Determined parameters of helimagnon dispersion

Challenges self-consistent renormalization theory for MnSi

Abstract

The temperature dependence of the manganese magnetic moment and the spin-lattice relaxation rate measured by the muon spin relaxation technique in the magnetically ordered phase of the chiral intermetallic cubic MnSi system are both explained in terms of helimagnon excitations of a localized spin model. The two free parameters characterizing the helimagnon dispersion relation are determined. A combined analysis of the two data sets cannot be achieved using the self-consistent renormalization theory of spin fluctuations which assumes the magnetism of MnSi to arise uniquely from electronic bands. As a result of this work, MnSi is proposed to be a dual electronic system composed of localized and itinerant magnetic electrons. Finally we note that the analysis framework can be applied to other helimagnets such as the magnetoelectric compound Cu2OSeO3.