2005/09/06 by G. D. Sanders, Christopher J. Stanton, C. J. Stanton +5 · 17 citations
Engineering · Physics and Astronomy · #Advanced Semiconductor Detectors and Materials #Atomic physics #Chalcogenide Semiconductor Thin Films #Condensed matter physics #Phonon #Physics #Relaxation (psychology) #Semiconductor Quantum Structures and Devices #Trapping #cond-mat.mes-hall #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevb.72.245302
published in Physical Review B 72(24) (American Physical Society) · 14 pages, 10 figures
arxiv created 2005/09/06 · openalex publication_date 2005/12/02 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present detailed theoretical calculations of two color, time-resolved pump-probe differential reflectivity measurements. The experiments modeled were performed on InxMn_1\ensuremath-xAs∕GaSb heterostructures and have shown pronounced oscillations in the differential reflectivity as well as a time-dependent background signal. Previously, we showed that the oscillations resulted from a generation of coherent acoustic phonon wave packets in the epilayer and were not associated with the ferromagnetism. Now we take into account not only the oscillations, but also the background signal which arises from photoexcited carrier effects. The two color pump-probe reflectivity experiments are modeled using a Boltzmann equation formalism. We include photogeneration of hot carriers in the InxMn_1\ensuremath-xAs quantum well by a pump laser and their subsequent cooling and relaxation by emission of confined LO phonons. Recombination of electron-hole pairs via the Schockley-Read carrier trapping mechanism is included in a simple relaxation time approximation. The time-resolved differential reflectivity in the heterostructure is obtained by solving Maxwell's equations and by comparing the experiments. Phase space filling, carrier capture and trapping, band-gap renormalization, and induced absorption are all shown to influence the spectra.