Measurements of the complex conductivity of NbxSi1-x alloys on the insulating side of the metal-insulator transition - art. no. 116602

Authors
Helgren, E Gruner, G Ciofalo, MR Baxter, DV Carini, JP
Citation
E. Helgren et al., Measurements of the complex conductivity of NbxSi1-x alloys on the insulating side of the metal-insulator transition - art. no. 116602, PHYS REV L, 8711(11), 2001, pp. 6602
Citations number
20
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007 → ACNP
Volume
8711
Issue
11
Year of publication
2001
Database
ISI
SICI code
0031-9007(20010910)8711:11<6602:MOTCCO>2.0.ZU;2-F
Abstract
We have conducted temperature and frequency dependent transport measurement s in amorphous NbxSi1-x samples in the insulating regime. We find a tempera ture dependent dc conductivity consistent with variable range hopping in a Coulomb glass. The frequency dependent response in the millimeter-wave freq uency range can be described by the expression sigma(omega)proportional to( -t omega)(alpha) with the exponent somewhat smaller than 1. Our ac results are not consistent with extant theories for the hopping transport.