Magnetic multipole analysis of kagome and artificial spin-ice dipolar arrays
نویسندگان
چکیده
We analyze 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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