Skyrmion Lattice in Two-Dimensional Chiral Magnet

Abstract

We develop a theory of the magnetic field-induced formation of Skyrmion crystal state in chiral magnets in two spatial dimensions, motivated by the recent discovery of the Skyrmionic phase of magnetization in thin film of Fe${}_{0.5}$Co${}_{0.5}$Si and in the A-phase of MnSi. Ginzburg-Landau functional of the chiral magnet re-written in the CP${}^1$ representation is shown to be a convenient framework for the analysis of the Skyrmion states. Phase diagram of the model at zero temperature gives a sequence of ground states, helical spin $\to$ Skyrme crystal $\to$ ferromagnet, as the external field $B$ increases, in good accord with the thin-film experiment. In close analogy with Abrikosov's derivation of the vortex lattice solution in type-II superconductor, the CP${}^1$ mean-field equation is solved and shown to reproduce the Skyrmion crystal state.

10 pages, 7 figures

References in corpus (3)

• Skyrmions and Anomalous Hall Effect in a Dzyloshinskii-Moriya Spiral Magnet
• Soft Spin Wave Near nu=1: Evidence for a Magnetic Instability in Skyrmion Systems
• NMR Study of Large Skyrmions in Al_{0.13}Ga_{0.87}As Quantum Wells

Cited by in corpus (8)

• Magnetic phase diagram of MnSi inferred from magnetization and ac susceptibility
• Compact Skyrmions, Merons and Bimerons in Thin Chiral Magnetic Films
• Giant Skyrmions Stabilized by Dipole-Dipole Interactions in Thin Ferromagnetic Films
• Magnetoelectric Resonances and Predicted Microwave Diode Effect of Skyrmion Crystal in Multiferroic Chiral-Lattice Magnet
• A mechanism to pin skyrmions in chiral magnets
• Field-Driven Evolution of Chiral Spin Textures in Thin Nanodisk of the Helimagnets
• Phase diagram of insulating crystal and quantum Hall states in ABC-stacked trilayer graphene
• Nature of an intermediate non-Fermi liquid state in Ge-substituted YbRh${}_2$Si${}_2$: Fermionized skyrmions, Lifshitz transition, Skyrmion liquid, and Gruneisen ratio