Anomalous crossover between thermal and shot noise in macroscopic diffusive conductors

We predict the existence of an anomalous crossover between thermal and shot noise in macroscopic diffusive conductors. We first show that, besides thermal noise, these systems may also exhibit shot noise due to fluctuations of the total number of carriers in the system. Then we show that at increasi...

Descripción completa

Detalles Bibliográficos
Autores: Gomila Lluch, Gabriel, Reggiani, L. (Lino), 1941-
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2000
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/10600
Acceso en línea:https://hdl.handle.net/2445/10600
Access Level:acceso abierto
Palabra clave:Soroll electrònic
Fluctuations (Physics)
Semiconductors
Electronic noise
Descripción
Sumario:We predict the existence of an anomalous crossover between thermal and shot noise in macroscopic diffusive conductors. We first show that, besides thermal noise, these systems may also exhibit shot noise due to fluctuations of the total number of carriers in the system. Then we show that at increasing currents the crossover between the two noise behaviors is anomalous, in the sense that the low-frequency current spectral density displays a region with a superlinear dependence on the current up to a cubic law. The anomaly is due to the nontrivial coupling in the presence of the long-range Coulomb interaction among the three time scales relevant to the phenomenon, namely, diffusion, transit, and dielectric relaxation time.