Low Temperature Physics: 30, 853 (2004); https://doi.org/10.1063/1.1819860 (5 pages)
Fizika Nizkikh Temperatur: Volume 30, Number 11 (November 2004), p. 1139-1145    ( to contents , go back )

Magnetotransport probing of quality of the interfaces of quantum wells in the valence band of Ge1-xSix/Ge/Ge1-xSix heterostructures and the symmetry of their potential profile

M.V. Yakunin, G.A. Alshanskii, Yu.G. Arapov, V.N. Neverov, G.I. Harus, N.G. Shelushinina

Institute of Metal Physics , S. Kovalevskoyi st. 18, Ekaterinburg 620219, Russia
E-mail: yakunin@imp.uran.ru

O.A. Kuznetsov

Physicotechnical institute at the Nizhniy Novgorod state university Nizhni Novgorod, 603600, Russia

A. de Visser, and L. Ponomarenko

Institute Van der Vaаl`sa-Zееmаnа, University of Amsterdam, Netherlands
pos Анотація:

Received June 24, 2004

Abstract

The hole gas within Ge layers of the multilayered p-type Ge/Ge1–xSix heterosystem is shown to be separated into two 2D sublayers located at the opposite Ge interfaces for layers wider than ~ 30 nm. This is evident from the disappearance of the quantum Hall plateau and concomitant magnetoresistance minimum for the filling factor n = 1. A positive magnetoresistance also arise in this case which is attributed to the existence of two kinds of holes of different mobilities. The quantitative analysis indicates that these are mainly heavy holes of different mobilities within the self-formed sublayers. The difference in mobilities suggests different qualities of the normal and inverted interfaces of the Ge layers. The considerable width of the v = 2 quantum Hall plateau and its correct vertical position indicate that the hole densities within the self-formed sublayers are similar, and thus the potential profile is (at least nearly) symmetrical.

PACS:
73.50.Jt - Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.20.-r - Electron states at surfaces and interfaces

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