Non-ergodicity and fluctuations in mesoscopic insulators: The replica cooperon and diffuson
Laboratorio de Física Estadística de
Sistemas Desordenados, Centro de Física, IVIC Apartado 21827, Caracas 1020A, Venezuela
2 Departamento de Física, Universidad Simón Bolívar Apartado 89000, Caracas 1080A, Venezuela
Accepted: 16 March 2001
We explore the mesoscopic conductance fluctuations in the insulating regime within the Nguyen, Spivak, and Shklovskii model. We find that fluctuations of the log-conductance are persistent above the decorrelation field Bc in the insulating regime. Using the replica approach, we derive the field coupling and fluctuations in terms of "cooperon"and "diffuson"analogs and determine new corrections to temperature dependencies for small . We also analyze the ergodicity of fluctuations in the log-conductance and its scaling properties, and discuss the asymptotic validity of the usual criterion involving the commutability of disorder and field fluctuation averages.
PACS: 72.20.-i – Conductivity phenomena in semiconductors and insulators / 73.50.Dn – Low-field transport and mobility; piezoresistance / 74.40.+k – Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.)
© EDP Sciences, 2001