Neutron scattering investigation of proposed Kosterlitz-Thouless transitions in the triangular-lattice Ising antiferromagnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>TmMgGaO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math>
Zhiling Dun, Marcus Daum, Raju Baral, Henry E. Fischer, Huibo Cao, Yaohua Liu, M. B. Stone, J. A. Rodriguez‐Rivera, Eun Sang Choi, Qing Huang, Haidong Zhou, Martin Mourigal, Benjamin A. Frandsen
Abstract
The Kosterlitz-Thouless transition describes a topological phase transition in the 2D XY model resulting from the binding of vortex-antivortex pairs. Kosterlitz-Thouless physics can theoretically emerge in triangular Ising antiferromagnets by mapping magnetic moments onto a complex order parameter residing at the center of each triangle of the lattice. Here, the authors find supporting evidence for such physics in the rare-earth material TmMgGaO${}_{4}$ through neutron scattering and modeling studies of spin correlations in both real and reciprocal space. This research shows that dense spin systems, even in the presence of structural disorder, can be investigated and controlled in search for topological phase transitions.