Universal Fano factor and anomalous I-V characteristics in weakly interacting quantum dots

• Autor(a) principal: Souza, André Maurício Conceição de
• Data de Publicação: 2005
• Outros Autores: Macedo, Antônio Murilo Santos
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: http://link.aps.org/doi/10.1103/PhysRevB.72.165340; https://ri.ufs.br/handle/riufs/464
• topic: Transporte eletrônico em sistemas mesoscópicos; Pontos quânticos

We study interaction effects in quantum dots coupled to perfectly conducting leads via barriers of arbitrary transparencies and embedded in an electromagnetic environment characterized by a fixed external impedance. Combining a recently proposed renormalization group equation for the semiclassical regime of this system with an extended version of circuit theory, we study the Fano factor and the I-V characteristics in the low-temperature and low-energy regime. The Fano factor exhibits a sequence of universal plateaus as a function of the transparencies of the barriers. We also show that a recently discovered quantum transition, at intermediate values of the barrier’s transparencies, leads to an anomalous transport regime characterized by a Fano factor that is the harmonic average of its values in adjacent plateaus. Our result extends a previous classification scheme for mesoscopic conductors.