Generation of high-frequency phonons with excitation of antiferromagnets by nonresonant parallel pumping
Annotatsiya
The generation of high-frequency phonons under the action of an alternating magnetic field with frequency Ω < 2ϵ0 (ϵ0 is the activation energy of the low-frequency branch of the spin wave spectrum) parallel to a constant field on an antiferromagnet is studied. It is shown that phonon generation occurs owing to the induction of magnon-phonon interactions by the alternating magnetic field. The sound waves, whose velocity is greater than the velocity of the spin wave, are generated in a narrow spectral region (its width is determined by the frequency of the alternating magnetic field). Phonons whose frequency exceeds the magnetic field frequency are generated in antiferromagnets in which the spin-wave velocity exceeds the sound velocity.