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arXiv · 0903.2626

Quantum effects in a weakly-frustrated S=1/2 two-dimensional Heisenberg antiferromagnet in an applied magnetic field

N. Tsyrulin·T. Pardini·R. R. P. Singh·F. Xiao·P. Link·A. Schneidewind·A. Hiess·C. P. Landee·M. M. Turnbull·M. Kenzelmann
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Abstract

We have studied the two-dimensional S=1/2 square-lattice antiferromagnet $Cu(pz)_2(ClO_4)_2$ using inelastic neutron scattering and series expansion calculations. We show that the presence of antiferromagnetic next-nearest neighbor interactions enhances quantum fluctuations associated with resonating valence bonds. Intermediate magnetic fields lead to a selective tuning of resonating valence bonds and a spectacular inversion of the zone-boundary dispersion, providing novel insight into 2D antiferromagnetism in the quantum limit.

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N. Tsyrulin, T. Pardini, R. R. P. Singh, F. Xiao, P. Link, A. Schneidewind, A. Hiess, C. P. Landee, M. M. Turnbull, M. Kenzelmann. 2009-03-15. Quantum effects in a weakly-frustrated S=1/2 two-dimensional Heisenberg antiferromagnet in an applied magnetic field. https://doi.org/10.1103/physrevlett.102.197201

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