G. A. Khodaparast

Ultrafast magneto-optics in ferromagnetic III–V semiconductors

We investigate various ultrafast optical processes in ferromagnetic (III,Mn)V semiconductors induced by femtosecond laser pulses. Two-colour timeresolved magneto-optical spectroscopy has been developed, which allows us to observe a rich array of dynamical phenomena. We isolate several distinct temporal regimes in spin dynamics, interpreting the fast (< 1p s) dynamics as spin heating through sp–d exchange interaction between photo-carriers and Mn ions while the ∼100 ps component is interpreted as a manifestation of spin– lattice relaxation. Charge carrier and phonon dynamics were also carefully studied, showing an ultrashort charge lifetime of photo-injected electrons (∼ 2p s) and propagating coherent acoustic phonon wavepackets with a strongly probe energy dependent oscillation period, amplitude and damping. (Some figures in this article are in colour only in the electronic version)

Temperature dependence of intersubband transitions in InAs/AlSb quantum wells

We have carried out a systematic temperature-dependent study of intersubband absorption in InAs/AlSb quantum wells from 5 to 10 nm well width. The resonance energy redshifts with increasing temperature from 10 to 300 K, and the amount of redshift increases with decreasing well width. We have modeled the transitions using eight-band k⋅p theory combined with semiconductor Bloch equations, including the main many-body effects. Temperature is incorporated via band filling and nonparabolicity, and good agreement with experiment is achieved for the temperature dependence of the resonance.

Electronic states and cyclotron resonance in n -type InMnAs

We present a theory for electronic and magneto-optical properties of n-type

Electrical properties of InSb quantum wells remotely doped with Si

{\mathrm{In}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As}

Observation of excitonic transitions in InSb quantum wells

magnetic alloy semiconductors in a high magnetic field

In situ grown Ge in an arsenic-free environment for GaAs/Ge/GaAs heterostructures on off-oriented (100) GaAs substrates using molecular beam epitaxy

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Band offset determination in the strained-layer InSb/AlxIn1−xSb system

We use an eight-band Pidgeon-Brown model generalized to include the wave vector

Ultrafast optical and magneto-optical studies of III–V ferromagnetic semiconductors

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Ultrahigh-field hole cyclotron resonance absorption in In 1 − x Mn x As films

dependence of the electronic states as well as

Application of terahertz quantum-cascade lasers to semiconductor cyclotron resonance

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