Realization of Ground-State Artificial Skyrmion Lattices at Room Temperature

Published

October 8, 2015

Author(s)

Dustin A. Gilbert, Brian B. Maranville, Andy L. Balk, Brian J. Kirby, Peter Fischer, Daniel T. Pierce, John Unguris, Julie A. Borchers, Kai Liu

Abstract

The topological nature of magnetic skyrmions deriving from broken symmetries leads to extraordinary static and dynamic properties that provide new insight in fundamental problems of magnetism and exciting potentials for exploitation in novel magnetic technologies. Prerequisite are systems exhibiting skyrmion lattice textures at ambient conditions, which have been elusive so far. Here, we demonstrate the realization of artificial Bloch skyrmion lattices over extended areas in their ground state at room temperature by patterning magnetic nanodots with in-plane easy axis on top of an underlayer thin film with strong perpendicular magnetic anisotropy (PMA). Circularity control is achieved by introducing geometric asymmetries into vortex-state nanostructures and confirmed by magnetometry and state-of-the-art magnetic imaging. Polarity control is introduced by a tailored magnetic field sequence during vortex nucleation and demonstrated in the isothermal remanent magnetization and topology-dependent magnetization reversal of the underlayer. A critical step is the imprinting of the vortex structure from the dots into the underlayer via suppression of the PMA by ion irradiation. The imprinted spin texture is identified directly with polarized neutron reflectometry, and confirmed by magnetoresistance measurements. Our results constitute a solid platform to further explore the properties and behavior of room temperature ground state artificial Bloch skyrmion lattices.

Citation

Nature Communications

Volume

6

Issue

8462

Pub Type

Journals

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Keywords

magnetism, nanotechnology, skyrmion, magnetic vortex, exchange interaction, neutron reflecometry

Citation

Gilbert, D. , , B. , Balk, A. , Kirby, B. , Fischer, P. , Pierce, D. , Unguris, J. , Borchers, J. and Liu, K. (2015), Realization of Ground-State Artificial Skyrmion Lattices at Room Temperature, Nature Communications, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=918518 (Accessed October 4, 2024)