2001/11/13 by Yu. G. Arapov, G. A. Alshanskii, G. A. Al’shanskiĭ +7
Physics and Astronomy · #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #Semiconductor materials and interfaces #cond-mat.mes-hall
paper · pdf · doi:10.1088/0957-4484/13/1/319
published as Nanotechnology 13 (2002) 86-93 · Accepted for publication in Nanotechnology
arxiv created 2001/11/13 · openalex publication_date 2002/01/22 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We have measured the temperature (0.1⩽ T ⩽15 K) and magnetic field (0⩽ B ⩽12 T) dependences of longitudinal and Hall resistivities for p-Ge 0.93 Si 0.07 /Ge multilayers with different Ge layer widths 10⩽ d w ⩽38 nm and hole densities p s = (1-5) × 10 15 m -2 . Two models for the long-range random impurity potential (the model with randomly distributed charged centres located outside the conducting layer and the model of the system with a spacer) are used for evaluation of the impurity potential fluctuation characteristics: the random potential amplitude, nonlinear screening length in the vicinity of integer filling factors (FFs) ν = 1 and 2 and the background density of states (DOS). The described models are suitable for an explanation of the unusually high value of DOS at ν = 1 and 2, in contrast to the short-range impurity potential models. For half-integer FFs the linear temperature dependence of the effective quantum Hall effect (QHE) plateau-to-plateau transition width ν 0 ( T ) is observed in contrast to scaling behaviour for systems with short-range disorder. The finite T →0 width of QHE transitions may be due to an effective low-temperature screening of smooth random potential owing to Coulomb repulsion of electrons.