Bohm-Aharonov and Kondo effects on tunneling currents in a mesoscopic ring

• Autor(a) principal: Davidovich, Maria Augusta
• Data de Publicação: 1997
• Outros Autores: Anda, Enrique V., Iglesias, Jose Roberto, Chiappe, Giuseppe
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/104220
• topic: Sistemas mesoscopicos; Efeito kondo; Efeito Aharonov-Bohm; Modelo de Anderson; Nivel de fermi

We present an analysis of the Kondo effect on the Bohm-Aharonov oscillations of the tunneling currents in a mesoscopic ring with a quantum dot inserted in one of its arms. The system is described by an Andersonimpurity tight-binding Hamiltonian where the electron-electron interaction is restricted to the dot. The currents are obtained using nonequilibrium Green functions calculated through a cumulant diagrammatic expansion in the chain approximation. It is shown that at low temperature, even with the system out of resonance, the Kondo peak provides a channel for the electron to tunnel through the dot, giving rise to the Bohm-Aharonov oscillations of the current. At high temperature these oscillations are important only if the dot level is aligned to the Fermi level, when the resonance condition is satisfied.