2002/04/04 by И. Л. Дричко, I. L. Drichko, A. M. Diakonov +11
Physics and Astronomy · #FOS: Physical sciences #Magnetic properties of thin films #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.cond-mat/0204101
Revtex 4, 7 pages, 7 fugres
arxiv created 2002/04/04 · openalex publication_date 2002/04/04 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using simultaneous measurements of the attenuation and velocity of surface acoustic waves propagating along GaAs/Al0.3Ga0.7As heterostructures, complex ac conductance of the latters has been determined. In the magnetic fields corresponding to the middles of the Hall plateaus both the ac conductance, σ(ω), and the sheet electron density, ns, in the two-dimensional conducting layer turn out to be dependent on the samples' cooling rate. As a result, the sample ``remembers'' the cooling conditions. The complex conductance is strongly dependent on an infrared illumination which also changes both σ(ω) and ns. Remarkably, the correlation between σ(ω) and ns is universal, i.e. it is independent of the way to change these quantities. The results are attributed to two-electron defects (so-called DX- centers) located in the Si doped layer.