Coherent Spin Oscillations in a Disordered Magnet

@article{Ghosh2002CoherentSO,
  title={Coherent Spin Oscillations in a Disordered Magnet},
  author={S. Ghosh and Raghuveer Parthasarathy and Thomas F. Rosenbaum and Gabriel Aeppli},
  journal={Science},
  year={2002},
  volume={296},
  pages={2195 - 2198}
}
Most materials freeze when cooled to sufficiently low temperature. We find that magnetic dipoles randomly distributed in a solid matrix condense into a spin liquid with spectral properties on cooling that are the diametric opposite of those for conventional glasses. Measurements of the nonlinear magnetic dynamics in the low-temperature liquid reveal the presence of coherent spin oscillations composed of hundreds of spins with lifetimes of up to 10 seconds. These excitations can be labeled by… 
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