N. P. Stepina, I. A. Verkhushin, A. V. Nenashev, A. V. Dvurechenskii, “Temperature-stimulated transition from a macroscopic to a mesoscopic behavior of the hopping conductivity in a quantum-dot ensemble”, Pis'ma v Zh. Èksper. Teoret. Fiz., 2015, Volume 102, Issue 5,Pages <nobr>344

CONDENSED MATTER

Temperature-stimulated transition from a macroscopic to a mesoscopic behavior of the hopping conductivity in a quantum-dot ensemble

N. P. Stepina^a, I. A. Verkhushin^ba, A. V. Nenashev^ab, A. V. Dvurechenskii^ab

^a Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
^b Novosibirsk State University, Novosibirsk, 630090, Russia

Abstract: A temperature-induced transition to the macroscopic behavior of the hopping conductivity is observed in Ge/Si quantum-dot heterostructures upon the investigation of light-induced mesoscopic fluctuations of the electric current in these heterostructures. It is shown that the temperature dependence of the relative amplitude of the fluctuations A is described by a power law $A\sim T^{-0.93}$, which corresponds to the temperature dependence of the correlation length of the percolation cluster $L_c\sim T^{-1.24}$ This result is in good agreement with the theoretical dependence $L_c(T)$. By considering the correspondence between the size of the structure and the transition temperature, the correlation length has been estimated as $\sim 130$ nm at $4.2$ K.

Received: 16.07.2015
Revised: 20.07.2015

DOI: 10.7868/S0370274X15170117