Partially suppressed shot noise in hopping conduction: observation in SiGe quantum wells
We have observed shot noise in the hopping conduction of two-dimensional carriers confined in a p-type SiGe quantum well at a temperature of 4 K. Moreover, shot noise is suppressed relative to its "classical" value 2eI by an amount that depends on the length of the sample and the carrier density. We have found a suppression factor to the classical value of about one-half for a 2 &mgr;m long sample, and of one-fifth for a 5 &mgr;m sample. In each case, the factor decreased slightly as the density increased toward the insulator-metal transition. We explain these results in terms of the characteristic length ( approximately 1 &mgr;m in our case) of the inherent inhomogeneity of hopping transport, obtained from percolation theory.
Kuznetsov
VV
Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, New York 11794-3800, USA.
Mendez
EE
Zuo
X
Snider
GL
Croke
ET