Anomalous Hall Effect
Mostrando 1-7 de 7 artigos, teses e dissertações.
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1. Emissão de elétrons por efeito de campo em dispositivos de grafeno
Since graphene was first isolated in 2004 by the micromechanical exfoliation of graphite, many research groups focused their works in studying the properties of this material. Graphene is a strictly bidimensional system very resilient to mechanical tension which presents high charge carriers mobilities, anomalous quantum hall effect observed even at room tem
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/03/2012
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2. Quantum dots: photodetectors, weak localization and counter-rotating edge states / Pontos-quânticos: fotodetectores, localização-fraca e estados de borda contra-rotativos
In this work we present transport properties of heterostructures with quantum-dots. Three subjects were exploited: on the first one, we observed anomalous quantum Hall plateaus, for wich we attributed to the existence of counter-rotating edge-states; on the second subject, we determined the decoherence time of the bidimensional electron system as a function
Publicado em: 2008
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3. Magneto-transporte no limite quantico em grafite e bismuto / Magnet transport in the quantum limit in graphite and bismuth
Esta tese é o resultado da investigação das propriedades elétricas e magnéticas de dois semimetais: bismuto (Bi) policristalino romboédrico e grafite pirolítica altamente orientada (HOPG). Inicialmente nós discutimos o efeito Hall no limite quântico, que acontece em amostras de grafite HOPG com certo grau de desordem e onde a desordem é reduzida. E
Publicado em: 2007
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4. "Spin and magnetic properties of the III-V group semiconductors" / "Propriedades magnéticas e de spin em semicondutores do grupo III-V"
We present the results of our investigations concerning MBE grown AlGaAs/GaAs parabolic quantum well (PQW) samples. We focused on the variation of the Landé g factor along the structure of the PQWs, which occur as a consquence of its dependence on the Al content on the alloy AlGaAs. The implications are studied by Hall and Shubnikov-de Haas measurements. Sh
Publicado em: 2006
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5. MagnetoresistÃncia em filmes e multicamadas magnÃticas
In this master dissertation, we have studied, at room temperature, magnetic and transport properties of metallic films and multilayer of different structures such as: single layer thin films, coupled trilayer, ferromagnetic/antiferromagnetic bilayer and spin valve. Phenomenological models, which take in account the most relevant magnetic free energy terms, w
Publicado em: 2005
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6. Magnetotransport and Hall ferromagnetism in magnetic semiconductor heterostructures / Magneto-transporte e ferromagnetismo Hall em heteroestruturas semicondutoras magnéticas
Digital magnetic heterostructures (DMHs) are semiconductor structures with magnetic impurities (Mn) restricted to some planar arrangements (monolayers) regularly spaced. In the presence of an external magnetic field, the sp-d exchange interaction between the localized magnetic moments and the itinerant carriers is responsible for a giant spin splitting, of t
Publicado em: 2004
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7. Gate-controlled magnetic properties of the magnetic semiconductor (Zn,Co)O
Electric field-controlled ferromagnetism of (Zn,Co)O is demonstrated via anomalous Hall effect measurements. The electron carrier concentration in this material is 1.65×1020 cm−3 as measured via ordinary Hall effect at 4 K, and an anomalous Hall effect is observed up to 6 K, but with no hysteresis at any temperature. With positive electric gate field, the
American Institute of Physics.