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.
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Received 6 June 2001 and Received in final form 16 October 2001
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Urbina, A., Díaz-Paniagua, C., Braña, A. et al. Hopping conductivity and activated transport in InxGa1-xAs quantum wells. Eur. Phys. J. B 24, 463–468 (2001). https://doi.org/10.1007/s10051-001-8699-9
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DOI: https://doi.org/10.1007/s10051-001-8699-9