title: Finite-temperature transitions in dipolar spin ice in a large magnetic field.
abstract: We use Monte Carlo simulations to identify the mechanism that allows for phase transitions in dipolar spin ice to occur and survive for an applied magnetic field H much larger in strength than that of the spin-spin interactions. In the most generic and highest symmetry case, the spins on one out of four sublattices of the pyrochlore decouple from the total local exchange+dipolar+applied field. In the special case where H is aligned perfectly along the [110] crystallographic direction, spin chains perpendicular to H show a transition to q=X long-range order, which proceeds via a one- to three-dimensional crossover. We propose that these transitions are relevant to the origin of specific heat features observed in powder samples of the Dy2Ti2O7 spin ice material for H above 1 Tesla.
authors.affiliation: Department of Physics, University of Waterloo, Ontario, Canada N2L 3G1.
authors.forename: Jacob P C
authors.initials: JP
authors.lastname: Ruff
authors.forename: Roger G
authors.initials: RG
authors.lastname: Melko
authors.forename: Michel J P
authors.initials: MJ
authors.lastname: Gingras