Crossover between ballistic and diffusive regime in 2D SiGe quantum well

Abstract

In this manuscript, we report a theoretical investigation of the magneto-conductivity (σ(B,T)) in the metallic side (where dσ/dt<0) of a low densities 2D hole system in SiGe at very low temperature (below 2K). We have reanalyzed the experimental data already prepared and published by Drichko et al. in [23]. The purpose of this study is to determine the dominant electronic transport regime by confronting the experience with current theories. Based on the Fermi-liquid approach and the ZNA theory, we have able to determine the régimes of electronic transport in 2D p-SiGe quantum well. Indeed, the careful analysis of the results shows the coexistence of the two electronic transport regimes: ballistic and diffusive and, above all, a transition from one regime to the other. At low magnetic field (less than 6T), the Fermi liquid parameter values are found negative and positive for the highest values of the parallel magnetic field. The results are consistent with recent works on graphene sample and other similar samples.