Search results for "Semiconducting gallium"

showing 3 items of 3 documents

Effects of rapid thermal annealing on the optical properties of low-loss 1.3μm GaInNAs∕GaAs saturable Bragg reflectors

2004

We report studies of the effect of rapid thermal annealing (RTA) on the optical properties of a low-loss 1.3 mum saturable Bragg reflector (SBR), consisting of a GaInNAs/GaAs single quantum well embedded in an AlAs/GaAs Bragg reflector grown monolithically on a GaAs substrate. RTA gives rise to a blueshift of the photoluminescence (PL) peak (and therefore of the excitonic absorption peak) and an enhancement of PL intensity, while the reflectivity properties including peak reflectivity and bandwidth are not degraded. Temperature dependent photoluminescence measurements show that the RTA-induced blueshift of photoluminescence consists of two components: one originating from the increase of op…

:Science::Physics::Optics and light [DRNTU]PhotoluminescenceMaterials scienceCondensed Matter::Otherbusiness.industrychemical beamPhysics::OpticsGeneral Physics and AstronomyNonlinear opticsCondensed Matter::Mesoscopic Systems and Quantum Hall EffectDistributed Bragg reflectorBlueshiftGallium arsenideCondensed Matter::Materials Sciencechemistry.chemical_compoundchemistryOptoelectronicsSemiconducting galliumRapid thermal annealingbusinessSemiconductor quantum wellsRefractive indexQuantum wellJournal of Applied Physics
researchProduct

Electric control of the spin Hall effect by intervalley transitions

2013

Controlling spin-related material properties by electronic means is a key step towards future spintronic technologies. The spin Hall effect (SHE) has become increasingly important for generating, detecting and using spin currents, but its strength-quantified in terms of the SHE angle-is ultimately fixed by the magnitude of the spin-orbit coupling (SOC) present for any given material system. However, if the electrons generating the SHE can be controlled by populating different areas (valleys) of the electronic structure with different SOC characteristic the SHE angle can be tuned directly within a single sample. Here we report the manipulation of the SHE in bulk GaAs at room temperature by m…

Electronic structureSpin currentsSpin Hall effectElectronElectronic structureCrystal symmetrySpin-polarized electronsElectron populationGallium arsenideQuantum mechanicsGeneral Materials ScienceSemiconducting galliumStrength of materials0912 Materials EngineeringRoom temperatureSpin-½Intervalley transitionPhysicsCouplingElectromotive forceCondensed matter physicsSpintronicsMechanical EngineeringMaterial systemsGeneral ChemistryCondensed Matter::Mesoscopic Systems and Quantum Hall EffectCondensed Matter PhysicsElectric controlHeavy metalsMechanics of MaterialsSpin Hall effectSpin-orbit couplingsMaterial propertiesNature Materials
researchProduct

Frequency influence on the hot-electron noise reduction in GaAs operating under periodic signals

2008

A Monte Carlo study of the role of the frequency on the hot-electron intrinsic noise reduction in an n-type GaAs bulk driven by two mixed cyclostationary electric fields is presented. Previous numerical results showed the possibility to reduce the diffusion noise under specific wave-mixing conditions. In this work the variations of the noise properties are investigated by computing and integrating the spectral density of the velocity fluctuations. We found that the effect of reduction of the noise level due to the addition of a second field at twice frequency is almost independent of the frequency.

PhysicsNoise temperatureCondensed matter physicsCyclostationary processNoise reductionNoise spectral densityMonte Carlo methodSemiconducting gallium arsenideGeneral Physics and AstronomySpectral densityVelocity fluctuationSettore FIS/03 - Fisica Della MateriaMonte Carlo methodPeriodic signalSpectral densityNoise generatorElectric fieldNoise abatementNoise (radio)Hot electrons
researchProduct