title: Classical-quantum crossover in magnetic stochastic resonance in uniaxial superparamagnets.
abstract: It is shown that the signal-to-noise ratio of the magnetic moment fluctuations in the magnetic stochastic resonance of a quantum uniaxial paramagnet of arbitrary spin value S subjected to a weak probing ac field H(t) = H cos Ωt and a dc bias magnetic field H(0) displays a pronounced dependence on S. The dependence arises from the quantum dynamics of spins which differs markedly from the magnetization dynamics of classical superparamagnets. In the large spin limit, S --> ∞, the quantum solutions reduce to those for a classical uniaxial superparamagnet.
authors.affiliation: Laboratoire de Mathématiques, Physique et Systèmes, Université de Perpignan Via Domitia, Perpignan, France.
authors.forename: Yuri P
authors.initials: YP
authors.lastname: Kalmykov
authors.forename: Serguey V
authors.initials: SV
authors.lastname: Titov
authors.forename: William T
authors.initials: WT
authors.lastname: Coffey
mesh_terms: D003198:Computer Simulation; D004581:Electronics; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D009622:Noise / Q000517:prevention & control; D011789:Quantum Theory