The spin dynamics of the two-dimensional (2D) triangular lattice antiferromagnets , , and is investigated by electron spin resonance. In these oxides, on approaching the Néel temperature from above, the divergence of the temperature dependent linewidth is well described in terms of a Berezinskii-Kosterlitz-Thouless scenario due to magnetic vortex-antivortex pairing. A refined analysis suggests analogies to the melting scenario of a 2D triangular lattice described by Nelson, Halperin, and Young.
- Received 25 May 2009
©2009 American Physical Society