Observation of a blue shift in the optical response at the fundamental band gap in Ga1-xMnxAs
نویسندگان
چکیده
We report the observation of a sharp band-edge response in spectrally resolved differential reflectivity experiments on GaMnAs, in contrast to linear optical experiments in which large band-tail effects are known to dominate. The differential reflectivity response exhibits a blue shift relative to results in GaAs and LT-GaAs, consistent with the valence-band model of ferromagnetism. Our results demonstrate the utility of nonlinear optical techniques for studying the electronic structure of III-Mn-V diluted magnetic semiconductors.
منابع مشابه
Investigation of the effect of amino-alcohol stabilizers on crystal structure, band gap and blue luminescence of Cu-doped ZnO nanoparticles prepared by sol-gel method
In this research, Zn0.97Cu0.03O nanoparticles are prepared by sol-gel method using various stabilizers (Mono, Di, and Tri-ethanolamine). The effect of stabilizers on the structural, morphological and optical properties of the nanoparticles were investigated. Study of X-ray diffraction pattern shows the hexagonal wurtzite structure of samples. The crystallite size, strain, stress, and deformatio...
متن کاملEllipsometric study of the electronic structure of Ga1−xMnxAs and low-temperature GaAs
We have measured the optical constants of Ga1−xMnxAs from 0.62 to 6 eV, using spectroscopic ellipsometry. The second derivatives of the dielectric function are examined through a critical point analysis, allowing us to inspect interband transitions from different points in kW space. The evolution of the band structure over a broad doping range is determined. Specifically, the E1 critical point ...
متن کاملPublication I
We develop the theory of the shift in the band edge caused by a strong exchange interaction between charge carrier spins and the spins of the localized magnetic electrons in ferromagnetic semiconductors. The one-particle Green function is derived by usingMatsubara’s temperature Green functions, and then an infiniteorder correction to the band edge due to the exchange interaction is determined f...
متن کاملDesigning voltage tunable single and multi-channel optical filter with 1DDPC nano-structure
An electro-optic tunable single and multi-channel optical filter based on one-dimensional defective photonic crystal (1DDPC) structure is proposed. A couple of externally tunable defects in arrangement of (AB)5D1(BA)D2(BA)5, where A and B are dielectric materials, D1 and D2 are the tunable defects are used. The defects are composed of the ferroelectric LiNbO3 crystals and two pairs of thin Ag l...
متن کاملWeak localization in Ga1-xMnxAs: Evidence of impurity band transport
We report the observation of negative magnetoresistance in the ferromagnetic semiconductor Ga1−xMnxAs, x=0.05–0.08, at low temperatures T 3 K and low magnetic fields 0 B 20 mT . We attribute this effect to weak localization. Observation of weak localization strongly suggests impurity band transport in these materials, since for valence band transport one expects either weak antilocalization due...
متن کامل