Electrodynamics of a Coulomb Glass in n-Type Silicon
Abstract
Measurements of the complex frequency dependent conductivity of uncompensated n-type silicon are reported. The experiments are done in the quantum limit, ℏω>kBT, across a broad doping range on the insulating side of the metal-insulator transition. The low energy linear frequency dependence is consistent with theories of a Coulomb glass, but discrepancies exist in the relative magnitudes of the complex components. At higher energies we observe a crossover to a quadratic frequency dependence that is sharper than expected. The concentration dependence gives evidence that the Coulomb interaction energy is the energy scale that determines this crossover.
- Publication:
-
Physical Review Letters
- Pub Date:
- November 2002
- DOI:
- 10.1103/PhysRevLett.89.246601
- arXiv:
- arXiv:cond-mat/0210472
- Bibcode:
- 2002PhRvL..89x6601H
- Keywords:
-
- 72.20.Ee;
- 71.30.+h;
- 71.45.Gm;
- 72.40.+w;
- Mobility edges;
- hopping transport;
- Metal-insulator transitions and other electronic transitions;
- Exchange correlation dielectric and magnetic response functions plasmons;
- Photoconduction and photovoltaic effects;
- Condensed Matter - Disordered Systems and Neural Networks;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 5 pages, 4 figures