Browsing by Author "Bhowmick, M."

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    Dynamics of photoexcited carriers and spins in InAsP ternary alloys
    Meeker, M. A.; Magill, Brenden A.; Merritt, T. R.; Bhowmick, M.; McCutcheon, K.; Khodaparast, Giti A.; Tischler, J. G.; McGill, S.; Choi, S. G.; Palmstrom, C. J. (AIP Publishing, 2013-06)
    The recent rapid progress in the field of spintronics involves extensive measurements of carrier and spin relaxation dynamics in III-V semiconductors. In addition, as the switching rates in devices are pushed to higher frequencies, it is important to understand carrier dynamic phenomena in semiconductors on femtosecond time-scales. In this work, we employed time and spin resolved differential transmission measurements; to probe carrier and spin relaxation times in several InAsP ternary alloys. Our results demonstrate the sensitivity of the spin and carrier dynamics in this material system to the excitation wavelengths, the As concentrations, and temperature. (C) 2013 AIP Publishing LLC.
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    Time-resolved differential transmission in MOVPE-grown ferromagnetic InMnAs
    Bhowmick, M.; Merritt, T. R.; Khodaparast, Giti A.; Wessels, B. W.; McGill, S. A.; Saha, D.; Pan, X.; Sanders, G. D.; Stanton, C. J. (American Physical Society, 2012-03-27)
    We measured time-resolved differential transmission in InMnAs for different pump/probe schemes as a function of temperature, laser fluence, and external magnetic field. We observed tunability of the carrier relaxation time. In addition, we found that the sign of the differential transmission changed as a function of probe wavelength. The electronic structure for InMnAs was calculated for B = 0, using an eight-band k.p model, which includes conduction and valence band mixing as well as coupling of electrons and holes to the magnetic Mn impurities. This allows us to explain some of the carrier dynamics and the sign changes in the differential transmission.