FMR study of magnetic anisotropy and interlayer exchange coupling in (Ga,Mn)As/GaAs/(Ga,Mn)As

ORAL

Abstract

An interplay between magnetic anisotropy and interlayer exchange coupling (IEC) in (Ga,Mn)As-based heterostructures was studied experimentally. Ferromagnetic resonance (FMR) measurements were performed on a series of (Ga,Mn)As/GaAs/(Ga,Mn)As trilayers with different thickness $d_ {\mathrm{GaAs}} $ of nonmagnetic GaAs spacer. The manifestation of single- or double-resonance spectra was a foundation for determining $d_ {\mathrm{GaAs}}$-dependent regimes of strong ($d_{\mathrm{GaAs}} \leq 3$ nm) and weak ($d_{\mathrm{GaAs}} \geq 12$ nm) IEC. Under weak IEC conditions, two resonances of different intensity were consistently addressed by means of Landau- Lifshitz model of magnetization dynamics and recognized as the acoustic (strong) and optic (weak) modes of FMR. The unexpected change in the ordering of acoustic/optic modes in FMR spectra on the rotation of applied magnetic field was explained by detailed evaluation of Zeeman split energy levels of the magnetization.

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Authors

  • K. Dziatkowski

    • University of Warsaw and University of Texas at Austin

  • Z. Ge

    • University of Notre Dame

  • X. Liu

    • University of Notre Dame

  • J. K. Furdyna

    • University of Notre Dame

  • B. Clerjaud

    • Institute des NanoSciences de Paris and Universite Pierre et Marie Curie

  • R. Jakiela

    • Polish Academy of Sciences

  • A. Barcz

    • Institute of Electron Technology

  • A. Twardowski

    • University of Warsaw