Berlin 2018 – wissenschaftliches Programm
TT 109.3: Vortrag
Freitag, 16. März 2018, 10:00–10:15, H 3005
Cluster-glass phase in pyrochlore XY antiferromagnets with quenched disorder — •Matthias Vojta1, Jose A. Hoyos2, Eric C. Andrade2, and Stephan Rachel1,3 — 1Technische Universität Dresden, Germany — 2Universidade de Sao Paulo, Brasil — 3University of Melbourne, Australia
We study the impact of quenched disorder (random exchange couplings or site dilution) on easy-plane pyrochlore antiferromagnets. In the clean system a magnetically ordered state is selected from a classically degenerate manifold via an order-by-disorder mechanism. In the presence of randomness, however, different states can be locally selected depending on details of the disorder configuration. Using a combination of analytical considerations and classical Monte-Carlo simulations, we argue that any long-range-ordered magnetic state is destroyed beyond a critical level of randomness where the system breaks into magnetic domains due to random exchange anisotropies, becoming therefore a glass of spin clusters, in accordance with the available experimental data.