A two-dimensional spin liquid in quantum kagome ice

• Published in: Nature communications Vol. 6; no. 1; p. 7421
• Main Authors: Carrasquilla, Juan, Hao, Zhihao, Melko, Roger G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.06.2015; Nature Publishing Group
• Subjects: 639/766/483/640; Humanities and Social Sciences; Magnetic fields; Monte Carlo simulation; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8421

Actively sought since the turn of the century, two-dimensional quantum spin liquids (QSLs) are exotic phases of matter where magnetic moments remain disordered even at zero temperature. Despite ongoing searches, QSLs remain elusive, due to a lack of concrete knowledge of the microscopic mechanisms that inhibit magnetic order in materials. Here we study a model for a broad class of frustrated magnetic rare-earth pyrochlore materials called quantum spin ices. When subject to an external magnetic field along the [111] crystallographic direction, the resulting interactions contain a mix of geometric frustration and quantum fluctuations in decoupled two-dimensional kagome planes. Using quantum Monte Carlo simulations, we identify a set of interactions sufficient to promote a groundstate with no magnetic long-range order, and a gap to excitations, consistent with a Z 2 spin liquid phase. This suggests an experimental procedure to search for two-dimensional QSLs within a class of pyrochlore quantum spin ice materials. Two-dimensional quantum spin liquid states, which retain spin disorder down to low temperatures, have never been realized experimentally. Here, the authors use quantum Monte Carlo methods to predict a new route to this state in rare-earth pyrochlore quantum spin ices under an applied (111) magnetic field.