Observation of Non-Gaussian Conductance Fluctuations at Low Temperatures in Si:P(B) at the Metal-Insulator Transition

Kar, Swastik and Raychaudhuri, AK and Ghosh, Arindam and Löhneysen, HV and Weiss, G (2003) Observation of Non-Gaussian Conductance Fluctuations at Low Temperatures in Si:P(B) at the Metal-Insulator Transition. In: Physical Review Letters, 91 (21). 216603/1-4.

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Abstract

We report investigations of conductance fluctuations (with 1/f alpha power spectra) in doped silicon at low temperatures (T<20 K) as it is tuned through the metal-insulator transition (MIT) by changing the carrier concentration n. The scaled magnitude of noise, gamma H, increases with decreasing T following an approximate power law gamma H/~T- beta. At low T, gamma H diverges as n decreases through the critical concentration n/c, accompanied by a growth of low-frequency spectral weight. The second spectrum and probability density of the fluctuations show strong non-Gaussian behavior below 20 K as n/nc decreases through 1. This is interpreted as the onset of a glassy freezing of the electronic system across the MIT.

Item Type:	Journal Article
Additional Information:	Copyright for this article belongs to American Physical Society (APS).
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	04 Nov 2004
Last Modified:	19 Sep 2010 04:17
URI:	http://eprints.iisc.ernet.in/id/eprint/2246

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