Transporte dependente de spin em nanofios semicondutores controlado via interação spin-órbita

• Main Author: Cunha, Iann
• Publication Date: 2019
• Format: Master thesis
• Language: por
• Source: Repositório Institucional da UFSCAR
• Download full: https://repositorio.ufscar.br/handle/20.500.14289/11678
• topic: Nanoestruturas semicondutoras; Spintrônica; Acoplamento spin-órbita; Rashba; Nanofio; Semiconductor nanostructures; Spintronics; Spin-orbit coulping; Rashba; Nanowire; CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DA MATERIA CONDENSADA::ESTRUTURAS ELETRONICAS E PROPRIEDADES ELETRICAS DE SUPERFICIES INTERFACES E PELICULAS; CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DA MATERIA CONDENSADA::TRANSP.ELETRONICOS E PROP. ELETRICAS DE SUPERFICIES;INTERFACES E PELICULAS

This work was dedicated to the theoretical study of semiconductor nanostructures aimed at the implementation of spin dependent electronic transport. The objective was to study the electron transport properties considering the Rashba spin-orbit interaction located in a certain spatial region. Different configurations were considered for the intensity of the Rashba interaction, external potential and external magnetic field applied to the nanowire. In this way, we understand the modulation of spin transport when it is projected in the z-direction through the combination of spin-orbit interaction and system dimensionalities. In particular, we find a semi-analytical solution capable of determining spin dependent transport properties. This semi-analytic solution was applied to the electronic transport in a nanowire, considering a strictly one-dimensional model and a quasi one-dimensional model employing the effective mass approximation (k-p method). In this case, the electrons confined in a nanowire cross a region where the spin-orbit coupling is present, which will modify its transmission. Under certain conditions, the interaction of Rashba causes a suppression of the transmission for certain energies of the incident electrons. Such suppression can be understood as being the effect of coupling a bound state with the states of the continuum. These results open a new perspective for the understanding of experimental results of electronic transport in nanowires.