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Hopping conductivity and activated transport in InxGa1-xAs quantum wells

  • A. Urbina
  • C. Díaz-Paniagua
  • A.F. Braña
  • F. Batallán
  • 44 Downloads

Abstract:

We present measurements of the diagonal Rxx and off-diagonal Rxy magnetoresistance under quantum Hall conditions on several high electron mobility transistors (HEMT) based on InxGa1-xAs quantum wells. From the magnetoresistance tensor we obtain the longitudinal conductivity σ xx . We study the transport mechanisms near the σ xx minima at temperatures ranging between 2 K and 35 K; activated transport is the dominant mechanism for temperatures above 7 K while variable range hopping conductivity is significant for lower temperatures. We show that electron-electron correlations should be taken into account to explain the conductivity vs temperature behaviour below 5 K. Finally, we study the behaviour of the localization length as a function of Landau level filling and obtain a critical exponent γ = 3.45±0.15.

PACS. 72.80.Ey III-V and II-VI semiconductors – 73.43.Qt Magnetoresistance – 72.20.Ee Mobility edges; hopping transport 

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Copyright information

© EDP Sciences, Springer-Verlag 2002

Authors and Affiliations

  • A. Urbina
    • 1
  • C. Díaz-Paniagua
    • 2
  • A.F. Braña
    • 2
  • F. Batallán
    • 2
  1. 1.Departamento de Electrónica, Tecnología de Computadoras y Proyectos, Universidad Politécnica de Cartagena, C/Doctor Fleming s/n, 30202 Murcia, SpainES
  2. 2.Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, Cantoblanco, 28049 Madrid, SpainES

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