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Title:
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Ultrafast magneto-optical spectroscopy of (III,manganese)V ferromagnetic semiconductors |
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Author:
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Wang, Jigang |
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Advisor:
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Kono, Junichiro |
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Degree:
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Doctor of Philosophy thesis |
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Abstract:
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This thesis describes magneto-optical processes in ferromagnetic (III,Mn)V semiconductors and their heterostructures induced by femtosecond laser pulses. Two-color ultrafast magneto-optical spectroscopy has been developed, which allows us to observe a rich array of dynamical phenomena that are absent in traditional nonmagnetic semiconductors or metallic/insulating magnets. We isolate several distinct temporal regimes in spin dynamics, interpreting the fast (< 1 ps) dynamics as spin heating through sp-d exchange interaction between photo-carriers and Mn ions while the ∼100 ps component as a manifestation of spin-lattice relaxation. Charge carrier and phonon dynamics were also carefully studied, showing an ultrashort charge lifetime of photoinjected electrons (∼ 2 ps) and propagating coherent acoustic phonon wavepackets with strongly probe energy dependent oscillation period, amplitude and damping. |
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Citation:
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Wang, Jigang. (2005) "Ultrafast magneto-optical spectroscopy of (III,manganese)V ferromagnetic semiconductors." Doctoral Thesis, Rice University. http://hdl.handle.net/1911/18989. |
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URI:
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http://hdl.handle.net/1911/18989 |
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Date:
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2005 |
