Zero bias anomaly in a two dimensional granular insulator

Autor: Ossi, Netanel, Bitton, Liora, Gutman, Dmitri B., Frydman, A.
Rok vydání: 2012
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.87.115137
Popis: We compare tunneling density of states (TDOS) into two ultrathin Ag films, one uniform and one granular, for different degrees of disorder. The uniform film shows a crossover from Altshuler-Aronov (AA) zero bias anomaly to Efros Shklovskii (ES) like Coulomb gap as the disorder is increased. The granular film, on the other hand, exhibits AA behavior even deeply in the insulating regime. We analyze the data and find that granularity introduces a new regime for the TDOS. While the conductivity is dominated by hopping between clusters of grains and is thus insulating, the TDOS probes the properties of an individual cluster which is "metallic".
Comment: 4 pages, 4 figures
Databáze: arXiv