2013/11/07 by Michel J. P. Gingras, Paul A. McClarty · 2 citations
Physics and Astronomy · #cond-mat.str-el #cond-mat.stat-mech
paper · pdf · doi:10.1088/0034-4885/77/5/056501
published as Rep. Prog. Phys. 77, 056501 (2014) · Review article; 29 pages, 8 figures, 1 table, 189 references, 12 footnotes
arxiv created 2013/11/07 · arxiv updated 2014/07/29
The spin ice materials, including Ho2Ti2O7 and Dy2Ti2O7, are rare earth pyrochlore magnets which, at low temperatures, enter a constrained paramagnetic state with an emergent gauge freedom. Remarkably, the spin ices provide one of very few experimentally realised examples of fractionalization because their elementary excitations can be regarded as magnetic monopoles and, over some temperature range, the spin ice materials are best described as liquids of these emergent charges. In the presence of quantum fluctuations, one can obtain, in principle, a quantum spin liquid descended from the classical spin ice state characterised by emergent photon-like excitations. Whereas in classical spin ices the excitations are akin to electrostatic charges, in the quantum spin liquid these charges interact through a dynamic and emergent electromagnetic field. In this review, we describe the latest developments in the study of such a quantum spin ice, focussing on the spin liquid phenomenology and the kinds of materials where such a phase might be found.