Realistic calculations of correlated incompressible electronic states in GaAs-AlxGa1xAs heterostructures and quantum wells

M. W. Ortalano, Song He, and S. Das Sarma
Phys. Rev. B 55, 7702 – Published 15 March 1997
PDFExport Citation

Abstract

We perform an exact spherical geometry finite-size diagonalization calculation for the fractional quantum Hall ground state in three different experimentally relevant GaAs-AlxGa1xAs systems: a wide parabolic quantum well, a narrow square quantum well, and a heterostructure. For each system we obtain the Coulomb pseudopotential parameters entering the exact diagonalization calculation by using the realistic subband wave function from a self-consistent electronic structure calculation within the local-density approximation (LDA) for a range of electron densities. We compare our realistic LDA pseudopotential parameters with those from widely used simpler model approximations in order to estimate the accuracies of the latter. We also calculate the overlap between the exact numerical ground state and the analytical Laughlin state as well as the excitation gap as a function of density. For the three physical systems we consider that the calculated overlap is found to be large in the experimental electron density range. We compare our calculated excitation gap energy to the experimentally obtained activated transport energy gaps after subtracting out the effect of level broadening due to collisions. The agreement between our calculated excitation gaps and the experimental measurements is excellent.

    DOI:https://doi.org/10.1103/PhysRevB.55.7702

    ©1997 American Physical Society

    Authors & Affiliations

    M. W. Ortalano

    • Department of Physics, University of Maryland, College Park, Maryland 20742

    Song He

    • AT&T Bell Laboratories, Murray Hill, New Jersey 07974

    S. Das Sarma

    • Department of Physics, University of Maryland, College Park, Maryland 20742

    References (Subscription Required)

    Click to Expand
    Issue

    Vol. 55, Iss. 12 — 15 March 1997

    Reuse & Permissions
    Access Options
    Author publication services for translation and copyediting assistance advertisement

    Authorization Required


    ×
    ×

    Images

    ×

    Sign up to receive regular email alerts from Physical Review B

    Log In

    Cancel
    ×

    Search


    Article Lookup

    Paste a citation or DOI

    Enter a citation
    ×