1,721,011 research outputs found
Size effect of semiconductor quantum wells in excitonic spin generation under drift
No full textThe excitonic spin polarization in dependence of the size of semiconductor quantum well (QW) was investigated by observing the two different circular polarizations of photoluminescence (PL). From the measurements of PL in QWs, it was found that there is a difference between the two different polarization conditions, which is caused by spin-dependent phase-space filling. The PL spin polarization was estimated from the signals of the left and right circularly polarized PL and was found to depend on the size of the wells as well as on the strength of the bias field. The effects of the size of the well and applied electric field on the excitonic PL spin polarization were studied.No Full Tex
Semiconductor spintronics and its requirements
No full textRequirements of the injection and detection of spin current in a semiconductor are crucial for semiconductor spintronic devices. By reviewing the potentials and the recent success and understanding, we demonstrate the techniques for the injection and detection of spin current in a semiconductor. However, as a particular emphasis is given for the electrical detection, the spin-dependent Hall effects are discussed in more details. The major obstacles and challenges in the development of such devices are also pointed out.Griffith Sciences, School of Natural SciencesNo Full Tex
Spin drift-diffusion and its crossover in semiconductors
No full textSpintronics" is based on the control and manipulation of electron spin instead of, or in addition to, its charge, leading to novel electronic devices (spintronic devices) such as spin field effect transistors (SFETs), spin storage/ memory devices or spin quantum computers, which hold the promise of reduced power consumption, faster operation and smaller size. This new book provides leading-edge research from around the globe on the materials, applications and devices associated with spintronics.Griffith Sciences, School of Natural SciencesNo Full Tex
Optical bright solitons in inhomogeneous fiber core media
No full textGriffith Sciences, School of Natural SciencesNo Full Tex
Electronics, Sprintronics and Orbitronics
No full textGriffith Sciences, School of Natural SciencesNo Full Tex
Observation of the anomalous Hall effect in GaAs
No full textGriffith Sciences, School of Natural SciencesNo Full Tex
Optical sensor protector using wide-bandgap semiconductors
No full textOptical power limiting is the increase of optical absorption with light intensity. Optical absorption in dependences of the light intensity and thickness of single crystals of wide-bandgap semiconductor cadmium iodide was studied using laser light. The transmission of the crystals was found to increase with increasing light intensity. However, at higher light intensity, an increase of optical absorption with intensity was observed. This power limiting characteristics was also found to depend on the thickness of the crystals. The findings resulting from this investigation might have potential applications in optical sensor protector using wide-bandgap semiconductors.Griffith Sciences, School of Natural SciencesNo Full Tex
Direct detection of electron spins and doping effects in spin-polarized electron transport in gallium arsenide
No full textThe spin Hall effect allows the direct detection of spins in semiconductors. In this study, electron spins in n-doped gallium arsenide are detected and the effects of n-type doping in gallium arsenide under drift are studied. It is found that the effects in the spin-polarized electron transport increase with increasing doping density in the moderate range, indicating that the introduction of n-type dopants increases the electron-spin lifetimes in gallium arsenide. However, the transport drifting by a high field shows no effects because of destroying the electron-spin polarization in n-doped gallium arsenide. The results are discussed in details.Griffith Sciences, School of Natural SciencesNo Full Tex
Quadratic dependence of the spin-induced Hall voltage on longitudinal electric field
No full textThe effect of optically induced spins in semiconductors in the low electric field is investigated. Here we report an experiment which investigates the effect of a longitudinal electric field (E) on the spin-polarized carriers generated by a circularly polarized light in semiconductors. Our experiment observes the effect as a spin-induced anomalous Hall voltage (VAH) resulting from spin-carrier electrons accumulating at the transverse edges of the sample. Unlike the ordinary Hall effect, a quadratic dependence of VAH on E is observed, which agrees with the results of the recent theoretical investigations. It is also found that VAH depends on the doping density. The results are discussed. 頲008 Elsevier B.V. All rights reserved.Griffith Sciences, School of Natural SciencesNo Full Tex
Electric field control photo-induced Hall currents in semiconductors
No full textWe generate spin-polarized carrier populations in GaAs and low temperature-grown GaAs (LT-GaAs) by circularly polarized optical beams and pull them by external electric fields to create spin-polarized currents. In the presence of the optically generated spin currents, anomalous Hall currents with an enhancement with increasing doping are observed and found to be almost steady in moderate electric fields up to not, vert, similar120 mV 孭1, indicating that photo-induced spin orientation of electrons is preserved in these systems. However, a field not, vert, similar300 mV 孭1 completely destroys the electron spin polarization due to an increase of the D'yakonov-Perel' spin precession frequency of the hot electrons. This suggests that high field carrier transport conditions might not be suitable for spin-based technology with GaAs and LT-GaAs. It is also demonstrated that the presence of the excess arsenic sites in LT-GaAs might not affect the spin relaxation by Bir-Aronov-Pikus mechanism owing to a large number of electrons in n-doped materials.Griffith Sciences, School of Natural SciencesNo Full Tex
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