Quantum Hall effect in p-Ge/Ge1-xSix heterostructures with low hole mobility

Электронные свойства низкоразмерных систем

Анотація

The apparent insulator—quantum Hall—insulator (I—QH—I) transition for filling factor n = 1 has been investigated in p-type Ge/Ge_1–xSi_x heterostructures with e_Ft / ħ ≈ 1. Scaling analysis is carried out for both the low- and high-field transition point. In low magnetic fields w_ct < 1 pronounced QH-like peculiarities for n = 1 are also observed in both the longitudinal and Hall resistivities. Such behavior may be evidence of a localization effect in the mixing region of Landau levels and is inherent for two-dimensional structures in a vicinity of the metal—insulator transition.