Realization of Rectangular Artificial Spin Ice and Direct Observation of High Energy Topology.

Autor: Ribeiro IRB; Laboratory of Spintronics and Nanomagnetism (LabSpiN), Departamento de Física, Universidade Federal de Viçosa, 36570-000, Viçosa, Minas Gerais, Brazil.; Instituto Federal do Espírito Santo, Alegre, 36570-900, Espírito, Santo, 29520-000, Brazil., Nascimento FS; Departamento de Física, Universidade Federal de Ouro Preto, 35931-008, João Monlevade, Minas Gerais, Brazil., Ferreira SO; Laboratory of Spintronics and Nanomagnetism (LabSpiN), Departamento de Física, Universidade Federal de Viçosa, 36570-000, Viçosa, Minas Gerais, Brazil., Moura-Melo WA; Laboratory of Spintronics and Nanomagnetism (LabSpiN), Departamento de Física, Universidade Federal de Viçosa, 36570-000, Viçosa, Minas Gerais, Brazil., Costa CAR; Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Zip Code 13083-970, Campinas, Sao Paulo, Brazil., Borme J; INL-International Iberian Nanotechnology Laboratory, 4715-330, Braga, Portugal., Freitas PP; INL-International Iberian Nanotechnology Laboratory, 4715-330, Braga, Portugal., Wysin GM; Department of Physics, Kansas State University, Manhattan, KS, 66506-2601, USA., de Araujo CIL; Laboratory of Spintronics and Nanomagnetism (LabSpiN), Departamento de Física, Universidade Federal de Viçosa, 36570-000, Viçosa, Minas Gerais, Brazil. dearaujo@ufv.br., Pereira AR; Laboratory of Spintronics and Nanomagnetism (LabSpiN), Departamento de Física, Universidade Federal de Viçosa, 36570-000, Viçosa, Minas Gerais, Brazil. apereira@ufv.br.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2017 Oct 25; Vol. 7 (1), pp. 13982. Date of Electronic Publication: 2017 Oct 25.
DOI: 10.1038/s41598-017-14421-w
Abstrakt: In this work, we have constructed and experimentally investigated frustrated arrays of dipoles forming two-dimensional artificial spin ices with different lattice parameters (rectangular arrays with horizontal and vertical lattice spacings denoted by a and b respectively). Arrays with three different aspect ratios γ = a/b = [Formula: see text], [Formula: see text] and [Formula: see text] are studied. Theoretical calculations of low-energy demagnetized configurations for these same parameters are also presented. Experimental data for demagnetized samples confirm most of the theoretical results. However, the highest energy topology (doubly-charged monopoles) does not emerge in our theoretical model, while they are seen in experiments for large enough γ. Our results also insinuate that the string tension connecting two magnetic monopoles in a pair vanishes in rectangular lattices with a critical ratio γ = γ c  = [Formula: see text], supporting previous theoretical predictions.
Databáze: MEDLINE
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