## Simonyan// Vestnik Leningr

- G.N.Belozerskii, K.A.Makarov, S.G.B.S.Pavlov
- Univ., 1986,
- 1986

1 Excerpt

- Published 2001

The supergenerator of superparamagnetic system quantum evolution is investigated in discrete orientation model (DOM). It is shown that the generator is J-self-adjoint one at the case of potential drift field agreed upon magnetic anisotropy of the sample investigated. Perturbation theory is used for spectral analysis. The qualitative dependence of resonance absorption spectrum on the relation between quantum and stochastic parameters is demonstrated. keywords: superoperator, superparamagnetic, M̈ossbauer spectroscopy Introduction Qualitative and quantitative description of relaxation Mössbauer spectra is based on choosing of some relaxation process model. In the most general model of motion of magnetic moment ~ M(t) suggested by Brown [1] this motion is considered like diffusion process on radius | ~ M | sphere in a drift field stipulated by the magnetic anisotropy of the pattern. Under Born’s approximation Móssbauer spectra line shape one can express in terms of resolvent of the generator of quantum evolution operator of a nucleus, averaged along all diffusion process ~ M(t) trajectories. But computation of averaged evolution operator is connected with solving of complicated differential equation system of partial derivatives and can not be done in analytical form. To avoid this difficulty phenomenological models are used, where magnetic moment ~ M(t)

@inproceedings{Buslov2001SupergeneratorOS,
title={Supergenerator of Superparamagnetic System in Discrete Orientation Model},
author={V. A. Buslov},
year={2001}
}