High harmonic generation and turbulence of magnetoelastic excitations in hematite single crystal

Abstract

Strongly nonlinear resonance of die longitudinal magnetoelastic wave in a hematite single crystal has been studied experimentally. Generation of more than 40 acoustic harmonics by means of a sinusoidal rf magnetic field has been observed in periodic oscillations. Two typical kinds of bifurcations evoked by the variation of external parameters (bias magnetic-field strength, rf field frequency, and amplitude) have been found. The first one corresponds to a slow automodulation of the periodic ultrasonic excitation. The second one is accompanied by fast chaotic oscillations in the temporal domain and by generation of a few incommensurate frequencies in the ultrasonic spectrum similarly to quasiperiodic scenarios of turbulence. © 1997 American Institute of Physics.