Interacting quantum rotors in oxygen-doped germanium
Materials Science
2009-11-11 v1 Disordered Systems and Neural Networks
Abstract
We investigate the interaction effect between oxygen impurities in crystalline germanium on the basis of a quantum rotor model. The dipolar interaction of nearby oxygen impurities engenders non-trivial low-lying excitations, giving rise to anomalous behaviors for oxygen-doped germanium (Ge:O) below a few degrees Kelvin. In particular, it is theoretically predicted that Ge:O samples with oxygen-concentration of 10cm show (i) power-law specific heats below 0.1 K, and (ii) a peculiar hump in dielectric susceptibilities around 1 K. We present an interpretation for the power-law specific heats, which is based on the picture of local double-well potentials randomly distributed in Ge:O samples.
Cite
@article{arxiv.cond-mat/0503197,
title = {Interacting quantum rotors in oxygen-doped germanium},
author = {Hiroyuki Shima and Tsuneyoshi Nakayama},
journal= {arXiv preprint arXiv:cond-mat/0503197},
year = {2009}
}
Comments
13 pages, 11 figures; to be published in Phys. Rev. B