Browsing by Author "Araujo, Clodoaldo Irineu Levartoski de"

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    Magnetic vortex crystal formation in the antidot complement of square artificial spinice.
    (2014) Araujo, Clodoaldo Irineu Levartoski de; Silva, Rodrigo da Costa; Ribeiro, Igor Renato Bueno; Nascimento, Fábio Santos; Felix, Jorlandio Francisco; Ferreira, Sukarno Olavo; Mól, Lucas Alvares da Silva; Melo, Winder Alexander de Moura; Pereira, Afranio Rodrigues
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    Realization of rectangular artificial spin ice and direct observation of high energy topology.
    (2017) Ribeiro, Igor Renato Bueno; Nascimento, F. S.; Ferreira Júnior, Silvio da Costa; Melo, Winder Alexander de Moura; Costa, C. A. R.; Borme, J.; Freitas, P. P.; Wysin, G. M.; Araujo, Clodoaldo Irineu Levartoski de; Pereira, Amanda Raimundi
    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 = 2, 3 and 4 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 = γc = 3, supporting previous theoretical predictions.