Magnetic Ordering of Dipolar Spin Ice in Moderate [111] Field

Abstract

This thesis explores the low temperature physics of the macroscopically degenerate system of dipolar spin ice in moderate fields applied along the [111] cubic axis. While most applications of field generically lift the macroscopic degeneracy, the [111] direction only partially removes this degeneracy leaving behind a large manifold of states known as dipolar kagome spin ice. Building on prior numerical sampling methods, we develop non-local statistical sampling techniques specifically tailored to the dipolar kagome spin ice regime, as well as considerations about system geometry to account for commensurabilities. We will find a long rage order sets in below T < 0.1 K between a range of fields of 0.02 < T | B | < 0.83 K. This long range order will prove to be sensitive to perturbations and exist among a host of other metastable states extremely close in energy. A final discussion on future work and the possible need for clustering algorithms or study of other related systems concludes this work.