IFLYSIB   05383
INSTITUTO DE FISICA DE LIQUIDOS Y SISTEMAS BIOLOGICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A Three Dimensional Kasteleyn Transition in Spin Ice: numerical studies using the Wang-Landau Algorithm
Autor/es:
FERREYRA, MARÍA VICTORIA; GRIGERA, SANTIAGO ANDRÉS
Lugar:
Buenos Aires
Reunión:
Congreso; 27th International Conference on Low Tempemperature Physics; 2014
Institución organizadora:
Departamento de Física de la Universidad de Buenos Aires
Resumen:
We studied the frustrated magnetic system Dy2Ti2O7 by means of computational simulations using the Wang-Landau algorithm (WLA). Dy2Ti2O7 has a pyrochlore structure, where the magnetically active sites form a lattice of corner-sharing tetrahedra. These moments behave Ising-like at low temperatures, pointing in or out of the elementary tetrahedra, with nearest neighbour ferromagnetic interactions. These interactions lead to geometric frustration which, in turn, gives origin to ice rules analog to Bernal-Fowler´s, where the two-in two-out configuration represents the energy ground state. Such a state presents a degeneracy which increases exponentially with system size. WLA allows us to obtain an estimate of the density of states (DOS) function for a given system without any prior knowledge of it, allowing us to compute the partition function. Using WLA, we obtained the DOS function of a spin ice model with nearest neighbours interactions and with a magnetic field applied on the [100] direction. We show the presence of a topological phase transition known as the Three Dimensional Kasteleyn Transition, characterized by the fact that at large fields, the ice rules prohibit local fluctuations in the limit of low temperature.