EstatÃstica de contagem de carga e efeitos de interferÃncia em sistemas mesoscÃpicos

AUTOR(ES)

Anderson Luiz da Rocha e Barbosa

DATA DE PUBLICAÇÃO

2009

RESUMO

In this thesis we presented a detailed study about full counting statistics of transmitted charge and accumulated phase and the quantum interference corrections to the average conductance and the average shot-noise power in non-ideal ballistic chaotic cavities. In the theoretical analysis of this mesoscopic system, we obtained analytical expressions for the first four charge and phase cumulants of a voltage- and a current-biased cavity, respectively, when the chaotic cavity is coupled to an impedance z0. Using the saddle-point approximation, we obtained analytical expressions for the probability distributions of transmitted charge and accumulated phase of chaotic cavities with symmetric barriers and tunnel junctions. In the case of a chaotic cavity with barriers of arbitrary transparency, we obtained a signature of a quantum transition associated with the formation of Fabry-PÂerot modes inside the cavity in the probability distribution of transmitted charge. This quantum transition is characterized by the emergence of an inverse square-root singularity on the transmission eigenvalue density and it was recently reported by MacËedo and Souza. We also analysed the corrections due to quantum interference of the first two charge cumulants. These quantum interference corrections are known as weak-localization corrections and were computed using two independent methods: random matrix theory and quantum circuit theory. The weak-localization correction of shot-noise power has an unexpected amplification-suppression transition as a function of both the number of open channels and the barriers transparencies. This effect leads to a conceptual change in the usual interpretation of the weak-localization correction. Finally, we studied a how the weak-localization correction is affected by an external magnetic field and by a spin - orbit interaction

ASSUNTO(S)

chaotic cavities cavidades caÃticas full counting statistics estatÃstica de contagem fisica quantum interference efeitos de interferÃncia

Documentos Relacionados

• EstatÃstica de contagem em sistemas hÃbridos normal-supercondutor
• Teoria de circuitos para a estatÃstica de contagem de carga
• ConfiguraÃÃo de vÃrtices e efeitos de interface em supercondutores mesoscÃpicos
• Transporte de partÃculas em sistemas mesoscÃpicos.
• Uma avaliaÃÃo estatÃstica da eficiÃncia do gasto pÃblico municipal no Brasil