Electric and magnetic field effects on the binding energy of a hydrogenic impurity in quantum well wires with different shapes (original) (raw)
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Effect of the electric field on a hydrogenic impurity in a quantum-well wire
Physica B: Condensed Matter, 1995
The ground state binding energy, the energy shift and the electric dipole moment of a hydrogenic impurity in a quantum-well wire subjected to an external electric field have been calculated. The variational ansatz for the wave function of the electron, that takes into account the effect of the finite barrier height, has been used. Numerical results for the case of GaAs quantum-well wire show a large influence of the electric field, the finite barrier height and the impurity position on the binding energy, the energy shift and the electric dipole moment.
Effect of temperature on the binding energy of a shallow hydrogenic impurity in a quantum well wire
Canadian Journal of Physics, 2009
In this work, we investigate the variation of the binding energy of an on-axis hydrogenic impurity in a cylindrical semiconductor GaAsalxGa1–xAs quantum well wire (QWW) with temperature, by taking into account the temperature dependance of the electron masses and dielectric constants in the quantum well and potential barrier region as well as the temperature dependence of the barrier height. This investigation is important in understanding the role such impurities can play in determining the transport properties of such systems. The results show enhancement of the binding energy as the temperature is decreased, specially for small values of wire radius.
Binding energy of shallow impurities in a polar quantum well wire
Physica B: Condensed Matter, 2001
The binding energy of an on-center donor impurity in cylindrical quantum well wire is investigated. The calculation is made within the e!ective mass approximation and using a variational approach. The electronic con"nement was modeled by a "nite deep potential well. The interaction of the charge carriers (electron and ion) with both the con"ned LO and SO phonons has been considered. Our results show that the binding energy and the electron e!ective mass depend on the size of the wire, the height of the potential barrier and the polaronic corrections. Furthermore, for a thin wire the binding energy depends also on the variation of the electron e!ective mass at the edge of the wire.
Physica B: Condensed Matter, 2009
We have studied the magnetic field effects on the diamagnetic susceptibility and binding energy of a hydrogenic impurity in a quantum well-wire by taking into account spatially dependent screening. Using the effective-mass approximation within a variational scheme, binding energy and diamagnetic susceptibility of donor are obtained as a function of the magnetic field, length of the square quantum well-wire for different impurity positions. It is shown that the magnetic field effects on diamagnetic susceptibility can be more important for donors in quantum well-wires over a large range of wire dimensions.
Journal of Physics: Conference Series, 2012
The hydrogenic impurity binding energy in cylindrical quantum well wire with a finite confining potential including both barriers of finite height and an applied electric and magnetic fields are studied. The polaron effect on the ground-state binding energy are investigated by means of Landau-Pekar variation technique. The results for the binding energy as well as polaronic correction with taking into account polar optical phonon confinement effect are obtained as a function of the applied fields for different position of the impurity. Our calculations are compared with previous results in quantum wires of comparable dimensions.
Journal of Physics and Chemistry of Solids, 2003
Within the effective-mass approximation, we have investigated the in¯uence of a strong magnetic ®eld on the ground state binding energy and the photon energy dependence of the photoionization cross-section of a shallow donor impurity in a quasi-one-dimensional rectangular quantum wire with in®nite and ®nite potential barriers, using a variational approach. It is found that the binding energy and the photoionization cross-section as a function of photon energy were drastically dependent on the sizes of the wire, the potential well heights and the applied magnetic ®eld. q
Magnetic field dependence of the binding energy of shallow donors in GaAs quantum-well wires
Superlattices and Microstructures, 2001
Using a variational procedure within the effective-mass approximation we have calculated the binding energies of shallow-donor impurities in cylindrical GaAs quantum-well wires, in an axial magnetic field and an infinite confinement potential. In contrast to the previous results in quantum wells, we have found that, in the magnetic field, the impurity binding energy may be increased or decreased as a function of the impurity location in the quantum wire. On the basis of analysis of the variation of the binding energy with magnetic field strength, a method is proposed for experimentalists to confirm the presence of a shallow donor in the vicinity of the wire boundary.