Papers by Author: V.K. Henner

Abstract: Various coherent magneto-dynamical effects can lead to the phenomenon qualitatively similar to optical super-radiation (SR). To realize SR for spins, a sample should be placed in a passive resonance circuit that, in response to the magnetization motion, generates a feedback magnetic field common for all the spins of the system. The electromagnetic radiation emitted by an assembly of nano-entities (molecules, dots, grains) by way of the feedback effect establishes their coherence thus greatly reducing the duration and enhancing the intensity of the deexcitation pulse.

Abstract: The idea of establishing coherent relaxation in an assembly of magnetic moments by placing it in a passive resonator [1, 2] is applied to the case of single-domain ferromagnetic nanoparticles. The magnetodynamics of a particle is governed by the Landau-Lifshitz equation modified by adding the resonator feedback field. The particle uniaxial magnetic anisotropy and the interparticle dipole-dipole interactions are taken into account.

Abstract: The goal of this work is to justify a possibility to obtain and observe coherent spin relaxation—the superradiation (SR) effect—in molecular nanomagnetic structures. We note that giant-spin molecules have the magnetic moments of the order of and possess substantial magnetic anisotropy. Moreover, to invoke SR, such a system should be polarized to a high extent. When put together, these factors rule out the conventional treatment used e.g. for optical SR, and invoke development of novel approaches.