Magnetic Subbands
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Magnetotransporte em poços-quânticos de AlGaAs/GaAs com diferentes formas de potencial / Magnetotransport in AlGzAs/GzAs quantum wells with different potential shapes
In this thesis we present studies of magnetotransport in double quantum wells (DQWs) in low magnetic fields and under application of an external electric field (gate potential). Measurements of magnetoresistance have been carried out in both linear and non-linear regime. We report on the observation of magneto-intersubband (MIS) oscillations for the first ti
Publicado em: 2009
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2. Effect of potential shape on the density of the impurity states in nanotube
We analyze the effect of the potential shape on the ground state energy of the off-axis neutral donor in GaAs/Ga1-xAl xAs cylindrical nanotube in the presence of the uniform magnetic field applied along the symmetry axis. To take into account the mixing of the low lying subbands we express the wave function as a product of combination of 1s and 2p x,y wave f
Brazilian Journal of Physics. Publicado em: 2006-09
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3. Optical properties of carbon nanotubes under external electric fields
We study the optical properties of carbon nanotubes within the single-band tight-binding approximation.The great number of one-dimensional-like subbands of the nanotubes lead to typical van Hove singularities on the local density of states. When a tube is under the influence of a laser beam, optical transitions are allowed between Van Hove singularities and
Brazilian Journal of Physics. Publicado em: 2006-06
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4. Estudo de interferência de elétrons em dispositivos mesoscópicos no limite Hall quântico
In this work we introduce the basic concepts required to understand how electronic interferometers work. The interferometers are semiconductor devices based in GaAs/AlGaAs heterojunctions where a high mobility two-dimensional electron gas is formed. The electron gas is confined in a small region of dimension comparable to its Fermi wavelength. In a high magn
Publicado em: 2006
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5. Transporte quântico em poços parabólicos largos / Transportation wide parabolic quantum wells
The gradual progress, or evolution, of the two-dimensional (2D) toward three-dimensional (3D) Landau states was studied in wide parabolic quantum Wells (W = 1000 6000 Å). As transport technique, we used measurements of the magnetoresistence in intense (B = 0 15 T) and tilted ( = 0 90°; perpendicular parallel) magnetic Field at low temperature (T = 50 Mk).
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/07/2003
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6. Landau levels in two and three-dimensional electron gases in a wide parabolic quantum well
Shubnikov-de Haas oscillations are measured in a wide parabolic quantum well with 6 subbands in a tilted magnetic fi eld. We find two types of oscillations. The oscillations at low magnetic field are shifted towards higher fields with tilted angles, and can be attributed to the two-dimensional Landau state at the bottom subband. The position of the second ty
Brazilian Journal of Physics. Publicado em: 2002-06
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7. Magnetic multilayers in Ga1-xMn xAs/GaAs struc
Mn in GaAs substitutes Ga as a p dopant and introduces a localized magnetic moment of 5/2. Ga1–xMn xAs (for x » 0.04) has been proved to be an extremely interesting material, for its intrincated transport and magnetic properties. In the first part of this work a s
Brazilian Journal of Physics. Publicado em: 2002-06
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8. Propriedades eletrônicas das heteroestruturas semicondutoras / Electronic properties of semiconductor heterostructures
Esta tese compõe-se de contribuições à física das propriedades eletrônicas das heteroestruturas semicondutoras. São investigadas propriedades eletrônicas das duas heteroestruturas básicas: o poço quântico e a super-rede. Considera-se o poço quântico dopado com impurezas rasas e estudam-se as suas propriedades eletrônicas nos regimes de poço
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/12/1990
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9. Propriedades eletrônicas do monocalcogenetos de Sm e de ligas do tipo Sm1-xMxS
We present a theoretical model to explain the valence transitions of Sm in Sm1-xMxS alloys, where M is a transition metal (e.g. Y or La) as a function of the concentration x. The system is described by a two-band model: a zero width band of energy E0 (the 4f-level of Sm) and a conduction band, which is treated in the coherent potencial approximation (CPA). T
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 1981