Biomedical subjects

C Serpico

Publications and source records attributed to C Serpico.

3 recordsLinked to original sources

PubMed2005

Magnetization switching and microwave oscillations in nanomagnets driven by spin-polarized currents.

A novel theoretical approach to magnetization dynamics driven by spin-polarized currents is presented. Complete stability diagrams are obtained for the case where spin torques and external magnetic fields are simultaneously present. Quantitative predictions are made for the critical currents and fields inducing magnetization switching, for the amplitude and frequency of magnetization self-oscillations, and for the conditions leading to hysteretic transitions between self-oscillations and stationary states.

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PubMed2001

Spin-wave instabilities in large-scale nonlinear magnetization dynamics.

The stability of large magnetization motions in systems with uniaxial symmetry subject to a circularly polarized radio-frequency field is analytically studied. Instability conditions valid for arbitrary values of the amplitude and frequency of the driving field are derived. In the limit of small motions, these conditions yield Suhl's theory of spin-wave instabilities for the case of ferromagnetic resonance. It is shown that the input powers capable of inducing spin-wave instabilities are bounded from both below and above, so that large enough motions are always stable. In addition, it is demonstrated that stability of uniform motions depends on their preparation history.

Journal Article↗

PubMed2001

Nonlinear magnetization dynamics under circularly polarized field.

Exact analytical results are presented for the nonlinear large motion of the magnetization vector in a body with uniaxial symmetry subject to a circularly polarized field. The absence of chaos, the existence of pure time-harmonic magnetization modes with no generation of higher-order harmonics, and the existence of quasiperiodic magnetization modes with spontaneous breaking of the rotational symmetry are proven. Application to ferromagnetic resonance and connection with the Stoner-Wohlfarth model are discussed.

Journal Article↗