1302.5185 (E. S. Tikhonov et al.)

Shot noise and a finite-size effect in a variable range hopping
conduction    [PDF]

E. S. Tikhonov, V. S. Khrapai, D. V. Shovkun, D. Schuh

We study a current shot noise in the regime of variable range hopping (VRH) conduction in a GaAs-based two-dimensional electron system. The Fano factor (F) of the shot noise is found to increase with decreasing temperature (T) and/or electron density. At the lowest T=0.5 K and in a sufficiently depleted sample the noise becomes Poissonian (F = 1 +/- 0.1), that correlates with an onset of a finite-size regime in the VRH conduction. In this regime, the sample length is comparable to a correlation length of a percolating network but still much larger than the average hop length. We propose a classical approach to explain the Poissonian noise value in such a system.

View original: http://arxiv.org/abs/1302.5185