Terahertz conductivity of thin gold films at the metal-insulator percolation transition

M. Walther, D. G. Cooke, C. Sherstan, M. Hajar, M. R. Freeman, and F. A. Hegmann
Phys. Rev. B 76, 125408 – Published 10 September 2007

Abstract

Terahertz time-domain spectroscopy is used to measure the complex conductivity of nanometer-thick gold films evaporated on silicon substrates in the far-infrared spectral region from 0.2to2.7THz. With increasing film thickness a characteristic crossover from an insulating to a conducting state via a percolation transition is observed. Of particular interest is the characteristic non-Drude behavior close to the transition. Whereas effective medium theory is inconsistent with our measurements in this regime, the Drude-Smith model, a generalization of the classical Drude model which incorporates carrier localization through backscattering, provides excellent fits to the observed complex conductivity. Applying this model we observe extreme values for the carrier scattering time at the percolation threshold.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 17 April 2007

DOI:https://doi.org/10.1103/PhysRevB.76.125408

©2007 American Physical Society

Authors & Affiliations

M. Walther*, D. G. Cooke, C. Sherstan, M. Hajar, M. R. Freeman, and F. A. Hegmann

  • Department of Physics, University of Alberta, Edmonton, Alberta T6G 2G7, Canada

  • *Present address: Institute of Physics, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany; markus.walther@physik.uni-freiburg.de
  • Present address:COMDTU, Department of Communications, Optics, and Materials, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
  • hegmann@phys.ualberta.ca

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 76, Iss. 12 — 15 September 2007

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×