AVS 45th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Friday Sessions
       Session MI-FrM

Paper MI-FrM11
Magnetization Induced Optical Second Harmonic Generation as a Readout of Thin Film Magnetic Memories

Friday, November 6, 1998, 11:40 am, Room 324/325

Session: Magnetization Dynamics and Magneto-Optics
Presenter: T.V. Murzina, Moscow State University, Russia
Authors: T.V. Murzina, Moscow State University, Russia
A.A. Fedyanin, Moscow State University, Russia
A.V. Melnikov, Moscow State University, Russia
T.V. Misuryaev, Moscow State University, Russia
O.A. Aktsipetrov, Moscow State University, Russia
Correspondent: Click to Email
The search for new materials for the magnetic memory devices gives rise to the search for new nondestructive readout techniques. In the present paper magnetization induced second harmonic generation (MSHG) is suggested as a readout for thin magnetic film-based memories. The advantage of the MSHG probe is a high sensitivity of quadratic nonlinear-optical response to the magnetic properties of nanostructures and low-dimensional systems. The fundamental wavelength can be chosen far from electronic resonance. That makes the MSHG probe nondestructive, while the MSHG wavelength can be resonant and thus provide an effective MSHG output sensitive to the magnetic state of the memory. In this paper, the results of systematic MSHG studies in thin magnetic films are presented which demonstrate the potential of this probe as a readout for thin film-based magnetic memories. Three systems are studied: Gd-containing Langmuir-Blodgett (LB) films, rare-earth iron garnet films, and magnetic Co-Cu nanogranular films. The output of a Q-switched YAG:Nd@super +3@ laser at 1064 nm, a pulse duration of 15 ns and an intensity of about 1 MW/cm@super 2@ is used as a fundamental radiation. DC-magnetic field up to 1.5 kOe is applied to the films in a longitudinal NOMOKE configuration. The MSHG readout is shown to be based either on the magneto-induced rotation of the polarization of the second harmonic (SH) wave polarization or on the magnetoinduced changes in the SHG intensity and magnetoinduced changes of the SH wave phase. It is shown that in nonresonant conditions, i.e. as both the fundamental and SH wavelength is far from electronic resonance of a magnetic film, the probability of the misreading (readout error) is rather small. Apart from three magnetic systems studied, the MSHG readout can be potentially used for a wide variety of magnetic storages based on thin film structures.