Impact of a topological defect and Rashba spin-orbit interaction on the thermo-magnetic and optical properties of a 2D semiconductor quantum dot with Gaussian confinement

• Published in: Physica. E, Low-dimensional systems & nanostructures Vol. 109; pp. 59 - 66
• Main Authors: Castaño-Yepes, Jorge David, Amor-Quiroz, D.A., Ramirez-Gutierrez, C.F., Gómez, Edgar A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2019
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2019.01.001

In this paper, we examine the effect of introducing a conical disclination on the thermal and optical properties of a two dimensional GaAs quantum dot in the presence of a uniform and constant magnetic field. In particular, our model consists of a single-electron subject to a confining Gaussian potential with a spin-orbit interaction in the Rashba approach. We compute the specific heat and the magnetic susceptibility from the exact solution of the Schrödinger equation via the canonical partition function, and it is shown that the peak structure of the Schottky anomaly is linearly displaced as a function of the topological defect. We found that such defect and the Rashba coupling modify the values of the temperature and magnetic field in which the system behaves as a paramagnetic material. Remarkably, the introduction of a conical disclination in the quantum dot relaxes the selection rules for the electronic transitions when an external electromagnetic field is applied. This creates a new set of allowed transitions causing the emergence of semi-suppressed resonances in the absorption coefficient as well as in the refractive index changes which are blue-shifted with respect to the regular transitions for a quantum dot without the defect. •The Schrödinger equation for a 2D-GaAs quantum dot with a topological defect is presented.•The effects of the spin-orbit Rashba coupling are included.•A set of new selection rules and transitions are found.•The topological defect modifies the paramagnetic behavior of the system.•The topological defect modifies the Schottky temperature and critical intensity.