{
  "id": "cond-mat/0204101",
  "version": "v1",
  "published": "2002-04-04T09:57:25.000Z",
  "updated": "2002-04-04T09:57:25.000Z",
  "title": "Memory effects in ac hopping conductance in the quantum Hall effect regime: Possible manifestation of DX$^-$ centers",
  "authors": [
    "I. L. Drichko",
    "A. M. Diakonov",
    "I. Yu. Smirnov",
    "V. V. Preobrazenskii",
    "A. I. Toropov",
    "Y. M. Galperin"
  ],
  "comment": "Revtex 4, 7 pages, 7 fugres",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "Using simultaneous measurements of the attenuation and velocity of surface acoustic waves propagating along GaAs/Al$_{0.3}$Ga$_{0.7}$As 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, $\\sigma (\\omega)$, and the sheet electron density, $n_s$, 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 $\\sigma (\\omega)$ and $n_s$. Remarkably, the correlation between $\\sigma (\\omega)$ and $n_s$ is \\emph{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.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2002-04-04T09:57:25.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quantum hall effect regime",
      "ac hopping conductance",
      "memory effects",
      "manifestation",
      "complex ac conductance"
    ],
    "note": {
      "typesetting": "RevTeX",
      "pages": 7,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2002cond.mat..4101D"
    }
  }
}