Double Barrier Potential
Mostrando 1-12 de 15 artigos, teses e dissertações.
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1. Collective coordinate analysis for double sine-Gordon model
Collective coordinate analysis for adding a space dependent potential to the double sine-Gordon model is presented. Interaction of solitons with a delta function potential barrier and also delta function potential well is investigated. Most of the features of interaction are derived analytically. We will find that the behaviour of a solitonic solution is lik
Brazilian Journal of Physics. Publicado em: 2010-03
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2. 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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3. Infinite potential barrier and hydrostatic pressure effects on impurity-related optical absorption spectra in GaAs double quantum wells
Using the effective-mass approximation and the variational method, we have calculated the effects of hydrostatic pressure on the donor- and acceptor-related optical absorption spectra in symmetrical GaAs double quantum well structures. A central finite potential barrier and two infinite external barriers constitute the profile of the potential barrier consid
Brazilian Journal of Physics. Publicado em: 2006-06
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4. A selfconsistent calculation of the transport properties of a double barrier spin filter
A double barrier resonant tunneling device in which the well is made of a semi-magnetic material can work as an efficient spin filter. Today it is possible to make semiconductors that are ferromagnetic at room temperature. Therefore the device studied here has a great potential to be used as a polarizer, an analyzer and other spintronic applications. We disc
Brazilian Journal of Physics. Publicado em: 2006-06
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5. Magnetopolaron effects on the intradonor 1s-2p+ transition energies in a GaAs - AlGaAs double quantum well
In this work we present a calculation of the intradonor 1s-2p+ transition energies for an impurity donor present in a GaAs-AlGaAs Double Quantum Well structure as a function of an applied external magnetic field. In our calculation the impurity energy levels were obtained from a variational method by choosing a Gaussian trial wave function, and the energy co
Brazilian Journal of Physics. Publicado em: 2006-06
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6. 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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7. Ressonâncias Stark e tunelamento em heteroestruturas semicondutoras. / Stark resonances and quantum tunnel effect in semiconductor heterostructures.
Neste trabalho determinamos a estrutura dos níveis dos estados quase-ligados e virtuais em sistemas de poços quânticos acoplados de AlGaAs-GaAs na presença de um campo elétrico externo (Voltagem) perpendicular às camadas semicondutoras. As heteroestruturas de AlGaAs-GaAs são modeladas por um conjunto de poços quânticos de potencial unidimensionais.
Publicado em: 1987
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8. H-bonded N-heterocyclic base-pair phototautomerizational potential barrier and mechanism: The 7-azaindole dimer
A theoretical analysis of the double proton transfer (PT) in a hydrogen-bonded N-heterocyclic base pair is presented. The calculated (time-dependent density functional theory) double PT barrier calculated for the concerted process of the 7-azaindole C2h dimer in the first excited singlet electronic state S1 conforms well to the kinetic data and the photophys
National Academy of Sciences.
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9. Force and kinetic barriers to unzipping of the DNA double helix
A theory of the unzipping of double-stranded DNA is presented and is compared to recent micromanipulation experiments. It is shown that the interactions that stabilize the double helix and the elastic rigidity of single strands simply determine the sequence-dependent ≈12-pN force threshold for DNA strand separation. Using a semimicroscopic model of the bin
The National Academy of Sciences.
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10. On the electronic nature of low-barrier hydrogen bonds in enzymatic reactions
The electronic nature of low-barrier hydrogen bonds (LBHBs) in enzymatic reactions is discussed based on combined low temperature neutron and x-ray diffraction experiments and on high level ab initio calculations by using the model substrate benzoylacetone. This molecule has a LBHB, as the intramolecular hydrogen bond is described by a double-well potential
The National Academy of Sciences.
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11. Transduction with recombinant adeno-associated virus for gene therapy is limited by leading-strand synthesis.
Adeno-associated virus is an integrating DNA parvovirus with the potential to be an important vehicle for somatic gene therapy. A potential barrier, however, is the low transduction efficiencies of recombinant adeno-associated virus (rAAV) vectors. We show in this report that adenovirus dramatically enhances rAAV transduction in vitro in a way that is depend
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12. Dynamics of the B–A transition of DNA double helices
Although the transition from the B-DNA double helix to the A-form is essential for biological function, as shown by the existence of the A-form in many protein–DNA complexes, the dynamics of this transition has not been resolved yet. According to molecular dynamics simulations the transition is expected in the time range of a few nanoseconds. The B–A tra
Oxford University Press.