Skyrmion Lattice in a Chiral Magnet

TL;DR

This paper reports the experimental observation of a skyrmion lattice in the chiral magnet MnSi, revealing a new form of topologically stable magnetic order stabilized by magnetic fields.

Contribution

It provides the first direct experimental evidence of a skyrmion lattice in a chiral magnet using neutron scattering techniques.

Findings

Skyrmion lattice forms spontaneously in MnSi.

Lattice stabilizes near the paramagnetism-helimagnetism boundary.

Magnetic order occurs regardless of magnetic field direction.

Abstract

Skyrmions represent topologically stable field configurations with particle-like properties. We used neutron scattering to observe the spontaneous formation of a two-dimensional lattice of skyrmion lines, a type of magnetic vortices, in the chiral itinerant-electron magnet MnSi. The skyrmion lattice stabilizes at the border between paramagnetism and long-range helimagnetic order perpendicular to a small applied magnetic field regardless of the direction of the magnetic field relative to the atomic lattice. Our study experimentally establishes magnetic materials lacking inversion symmetry as an arena for new forms of crystalline order composed of topologically stable spin states.