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arXiv · 0906.3937

Magnetic multipole analysis of kagome and artificial ice dipolar arrays

Gunnar Moller·R. Moessner
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Abstract

We analyse an array of linearly extended monodomain dipoles forming square and kagome lattices. We find that its phase diagram contains two (distinct) finite-entropy kagome ice regimes - one disordered, one algebraic - as well as a low-temperature ordered phase. In the limit of the islands almost touching, we find a staircase of corresponding entropy plateaux, which is analytically captured by a theory based on magnetic charges. For the case of a modified square ice array, we show that the charges ('monopoles') are excitations experiencing two distinct Coulomb interactions: a magnetic 'three-dimensional' one as well as a logarithmic `two dimensional' one of entropic origin.

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Gunnar Moller, R. Moessner. 2009-06-22. Magnetic multipole analysis of kagome and artificial ice dipolar arrays. https://doi.org/10.1103/physrevb.80.140409

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