2009/06/30 by Gunnar Moller, R. Moessner · 1 citation
Physics and Astronomy · #cond-mat.stat-mech #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.80.140409
published as Phys. Rev. B 80, 140409(R) (2009) · 4 pages, 2 figures; v2: minor changes as in final published version
arxiv created 2010/07/30 · arxiv updated 2010/08/02
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.