Estudo sobre os efeitos da massa efetiva anisotrópica nas propriedades eletrônicas, magnetização e corrente persistente em anel quântico semicondutor com geometria cônica

Abstract

Quantum rings are two-dimensional mesoscopic devices which have been increasingly investigated due to their relations with important physical phenomena such as Aharonov- Bohm effect, conductance oscillations and persistent currents. Moreover, recent works have been demonstrated interest for the characterization of their physical properties such as optical and conductivity properties as well as for the development of applications in spintronics field. In this work, it is considered a sample containing 1400 non-interacting electrons confined in a semiconductor quantum ring with conical geometry made of gal- lium arsenide (GaAs) and subjected to an Aharonov-Bohm flux passing perpendicularly through the ring center and to an uniforme magnetic field reaching the entirely ring sur- face parallel to the flux direction. The effects in the physical properties resulted from the inclusion of an anisotropic effective mass are investigated. From the numerical analyses, the results indicate that anisotropy affects significantly both shapes and levels of the sub- bands and, consequently, the total Fermi energy of the electron gas. Furthermore, it was observed that both magnetization and persistent current amplitudes in the weak magnetic field regime as well as the orbital gap value vary depending on the relation between the different effective masses, providing a possibility of refinement on these properties.