Temperature and hydrostatic pressure effects on the electronic structure, optical properties of spherical segment quantum dot/wetting layer and group velocity of light

Abstract

To investigate hydrostatic pressure and temperature effects on electron energy levels of an InAs spherical segment quantum dot with wetting layer embedded in GaAs barrier, we use the finite element method to solve the Schrödinger equation in the effective mass approximation. Results show that the ground, the first and the second excited state energies decrease (increase) as the hydrostatic pressure (temperature) increases for the constant temperature (pressure). Moreover, given the optical properties of the system interacting with two laser fields, red (blue) shifts are observed in the linear and nonlinear absorptions and dispersions for the probe pulse as the hydrostatic pressure (temperature) increases. Furthermore, as the hydrostatic pressure increases, the maximum of the group velocity of light inside the slow light frequency range increases and the slow light frequency range shifts to the lower probe frequencies.

Tuning the Diamagnetic Susceptibility and Electron Average Position in a GaAs Hemi-Spherical Quantum Dot with an Off-Center Donor Atom

“…The advances in nanotechnology have made possible to fabricate different shapes of semiconductor nanosystems such as island, cubic, cylindrical and spherical quantum dots (QDs) by using complex technologies who have used the molecular beam epitaxy (MBE) [1][2][3]. Due to the practical interest of the spherical QD, it is possible to study the hemi-spherical QD thanks to their quantum confinement and physical properties [4][5][6][7]. These immense properties lead to improve the new optical and bionanotechnology devices.…”

“…The hemi-spherical QD can be described by the confinement potential, the energy spectrum of a single-electron confined and their energy states. In this sense, the electronic structure of hemispherical QD in the presence and absence of donor impurity has been reported [5,6] using the finite element method. They have shown that the dispersions and absorptions are augmenting and exhibit blue-shifts as QD size decreases.…”