Abstract
The analogy between spin configurations in spin ice materials like $Ho_2Ti_2O_7$ and proton configurations in water ice, $H_2O$, has been appreciated for many years (see Bramwell and Gingras, Science, 294, 1495, 2001). However it is only in the last few years that this equivalence has been extended into the realm of electrodynamics. In this talk I shall describe our recent experimental work that identifies magnetic charges ("monopoles"), transient magnetic currents ("magnetricity") and the universal properties expected of an ideal magnetic Coulomb gas (magnetic electrolyte - "magnetolyte"). These universal properties include the Onsager-Wien effect, "corresponding states" behaviour, Debye-Huckel screening and Bjerrum pairing. I will describe experimental results for both traditional spin ice materials ($Ho_2Ti_2O_7$, $Dy_2Ti_2O_7$) and a recently discovered system ($Dy_2Ge_2O_7$).