Anomalous Hall Effect and Magnetic Monopoles in Momentum-Space

TL;DR

This paper demonstrates the existence of magnetic monopoles in the crystal-momentum space of solids, specifically in SrRuO3, through experimental evidence and first-principles calculations related to the anomalous Hall effect.

Contribution

It introduces the concept of magnetic monopoles in momentum space and provides experimental and computational evidence for their presence in a real material.

Findings

Evidence of magnetic monopoles in SrRuO3's momentum space

Correlation between anomalous Hall effect and monopole presence

First-principles calculations supporting experimental results

Abstract

Efforts to find the magnetic monopole in real space have been made in cosmic rays and in accelerators, but up to now there is no firm evidence for its existence due to the very heavy mass $\sim 10^{16}$GeV. However, we show that the magnetic monopole can appear in the crystal-momentum space of solids in the accessible low energy region ($\sim0.1-1$eV) in the context of the anomalous Hall effect. We report experimental results together with first-principles calculations on the ferromagnetic crystal SrRuO$_3$ that provide evidence for the magnetic monopole in the crystal-momentum space.