Browsing by Author "Wojtowicz, T."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Relaxation of photoinduced spins and carriers in ferromagnetic InMnSb films
    Nontapot, K.; Kini, Rajeev N.; Gifford, A.; Merritt, T. R.; Khodaparast, Giti A.; Wojtowicz, T.; Liu, X.; Furdyna, J. K. (AIP Publishing, 2007-04)
    The authors report time resolved measurements and control of photoinduced spin and carrier relaxations in InMnSb ferromagnetic films with 2% Mn content (grown by low-temperature molecular beam epitaxy) using femtosecond laser pulses, and compare them to analogous measurements on InBeSb and InSb films. In this work, magneto-optical Kerr effect and standard pump-probe techniques provided a direct measure of the photoexcited spin and carrier lifetimes, respectively. They observe decrease in relaxations times in the high laser fluence regime and an absence of temperature dependence of the relaxation times. (c) 2007 American Institute of Physics.
  • Thumbnail Image
    Time resolved magneto-optical studies of ferromagnetic InMnSb films
    Frazier, M.; Kini, Rajeev N.; Nontapot, K.; Khodaparast, Giti A.; Wojtowicz, T.; Liu, X.; Furdyna, J. K. (AIP Publishing, 2008-02)
    We report time resolved magneto-optical measurements in InMnSb ferromagnetic films with 2% and 2.8% Mn contents grown by low temperature molecular beam epitaxy. In order to probe a possible interaction between the spins of photoexcited carriers and the Mn ions, we measured spin dynamics before and after aligning the Mn ions by applying an external magnetic field at temperatures above and below the samples' Curie temperatures. We observed no significant temperature or magnetic field dependence in the relaxation times and attribute the observed dynamics entirely to the relaxation of photoexcited electrons in the conduction band where the s-d coupling with the localized Mn ions is significantly weaker compared to the p-d exchange coupling. We observed several differences in the optical response of our InMnSb samples which could have been influenced mainly by the samples' growth conditions. (c) 2008 American Institute of Physics.