Berlin 2012 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 47: Correlated Electrons: Spin Systems and Itinerant Magnets 2
TT 47.3: Vortrag
Freitag, 30. März 2012, 10:00–10:15, H 0104
The Physics of Charge Ice in Relation to the Spin Ices — Aroon O'Brien1,2, •Paul McClarty1, Frank Pollmann1, and Roderich Moessner1 — 1Max Planck Institute PKS, Dresden, Germany — 2School of Physics, The University of Sydney, Sydney, Australia
We consider a classical system of charges on the sites of a pyrochlore lattice in the presence of long-range Coulomb interactions. This model, which we call the charge ice model, appeared in the early literature exploring the Verwey transition in magnetite. We revisit this model in the context of recent work on Coulomb phases in condensed matter. In particular, we find many parallels and some subtle differences between the properties of charge ice and those of another model with long-range interactions - the dipolar spin ice model - which has been studied extensively and accounts very well for much of the phenomenology of the spin ice magnets. The Coulomb phase of both models is inherited from their short-range interacting counterparts. We study in detail the degeneracy breaking brought about by the long-range interactions as well as its effects on the thermal properties of the Coulomb phase. Finally, we comment on possible experimental signatures of the Coulomb physics in mixed valence materials.