U. Yesilgul

The effect of magnetic field on the impurity binding energy of shallow donor impurities in a Ga1−xInxNyAs1−y/GaAs quantum well

Using a variational approach, we have investigated the effects of the magnetic field, the impurity position, and the nitrogen and indium concentrations on impurity binding energy in a Ga1−xInxNyAs1−y/GaAs quantum well. Our calculations have revealed the dependence of impurity binding on the applied magnetic field, the impurity position, and the nitrogen and indium concentrations.

Photoionization of donor impurities in quantum wires in a magnetic field

Using a variational approach, we have calculated the impurity position dependence of the photoionization cross-section and the binding energy of a hydrogenic donor impurity in a quantum well wire in the presence of the magnetic field as a function of the photon energy. Our calculations have revealed the dependence of the photoionization cross-section and the impurity binding on the applied magnetic field, the size of the wire and the impurity position.

THE PHOTOIONIZATION CROSS-SECTION AND BINDING ENERGY OF IMPURITIES IN QUANTUM WIRES: EFFECTS OF THE ELECTRIC AND MAGNETIC FIELD

Using a variational approach, we have calculated the impurity position dependence of the photoionizaton cross-section and the binding energy for a hydrogenic donor impurity in a quantum well wire in the presence of the electric and magnetic field as a function of the photon energy. Our calculations have revealed the dependence of the photoionizaton cross-section and the impurity binding on the applied electric and magnetic field, and the impurity position.

OPTICAL INTERSUBBAND TRANSITIONS AND BINDING ENERGIES OF DONOR IMPURITIES IN Ga1-xInxNyAs1-y/GaAs/Al0.3Ga0.7As QUANTUM WELL UNDER THE ELECTRIC FIELD

The effects of nitrogen and indium mole concentration on the intersubband optical absorption for (1–2) transition and the binding energy of the shallow-donor impurities in a Ga1-xInxNyAs1-y/GaAs/Al0.3Ga0.7As quantum well under the electric field is theoretically calculated within the framework of the effective-mass approximation. Results are obtained for several concentrations of nitrogen and indium, and the applied electric field. The numerical results show that the intersubband transitions and the impurity binding energy strongly depend on the nitrogen and indium concentrations.

Effects of an Intense Laser Field and Hydrostatic Pressure on the Intersubband Transitions and Binding Energy of Shallow Donor Impurities in a Quantum Well

We have calculated the intersubband transitions and the ground-state binding energies of a hydrogenic donor impurity in a quantum well in the presence of a high-frequency laser field and hydrostatic pressure. The calculations are performed within the effective mass approximation, using a variational method. We conclude that the laser field amplitude and the hydrostatic pressure provide an important effect on the electronic and optical properties of the quantum wells. According to the results obtained from the present work, it is deduced that (i) the binding energies of donor impurity decrease as the laser field increase, (ii) the binding energies of donor impurity increase as the hydrostatic pressure increase, (iii) the intersubband absorption coefficients shift toward lower energies as the hydrostatic pressure increases, (iv) the magnitude of absorption coefficients decrease and also shift toward higher energies as the laser field increase. It is hopeful that the obtained results will provide important improvements in device applications.

THE ELECTRIC FIELD DEPENDENCE OF THE PHOTOIONIZATION CROSS-SECTION OF SHALLOW DONOR IMPURITIES IN QUANTUM DOTS: INFINITE AND FINITE MODEL

Using a variational approach, we have calculated the photo-ionization cross-section of a shallow donor impurity in a quantum dot with finite and infinite potential barriers in the presence of an electric field as a function of the photon energy. Our calculations have revealed the dependence of the photoionization cross-section on the electric field, the size of the quantum dot and the impurity position.

Effects of an intense, high-frequency laser field on bound states in Ga1 − xInxNyAs1 − y/GaAs double quantum well

Within the envelope function approach and the effective-mass approximation, we have investigated theoretically the effect of an intense, high-frequency laser field on the bound states in a GaxIn1 − xNyAs1 − y/GaAs double quantum well for different nitrogen and indium mole concentrations. The laser-dressed potential, bound states, and squared wave functions related to these bound states in Ga1 − xInxNyAs1 − y/GaAs double quantum well are investigated as a function of the position and laser-dressing parameter. Our numerical results show that both intense laser field and nitrogen (indium) incorporation into the GaInNAs have strong influences on carrier localization.

THE EFFECTS OF TEMPERATURE AND HYDROSTATIC PRESSURE ON THE DIAMAGNETIC SUSCEPTIBILITY OF A DONOR IN A QUANTUM WELL

Using the effective-mass approximation within a variational scheme, we have calculated the diamagnetic susceptibility and binding energy of a hydrogenic donor in a quantum well under different temperatures and hydrostatic pressure conditions. Our calculation have revealed the dependence of the diamagnetic susceptibility and the impurity binding on temperature and hydrostatic pressure.

Infrared transitions between hydrogenic states in GaInNAs/GaAs quantum wells

The effects of nitrogen and indium concentrations on the 1s, 2s, 2p0 and 2p±-like donor impurity energy states in a single Ga1−xInxNyAs1−y/GaAs quantum well (QW) are investigated by variational approach within the effective mass approximation. The results are presented as a function of the well width and the donor impurity position. It is found that the impurity binding and transition energies depend strongly on the indium concentration while depends weakly on the nitrogen concentration.