Antiferromagnetic Spin-Wave Frequencies in (C₂H₅NH₃)₂CuCl₄ by Parallel Pumping Experiments

Abstract

By parallel pumping experiments antiferromagnetic spin-wave frequencies at the Brillouin-zone-boundary in (C₂H₅NH₃)₂CuCl₄ have been measured as a function of static magnetic fields below the spin-flop critical field. The experimental results are in good agreement with the spin-wave theory which includes the effect of the magnetic dipolar interaction. Measurements have been done at pumping frequencies from 7.7 to 10.8 GHz and in the temperature range from 1.4 to 2.6 K. The instability threshold of the zone-boundary magnons is empirically described as H_1c=0.30×T^2.46 Oe.