Composite Fermion Spin Polarization Energy with Finite Layer Thickness

ORAL

Abstract

We study the spin polarization transitions of fractional quantum Hall (FQH) states in the filling range $1 < \nu < 2$ in symmetric quantum wells (QWs), as a function of density. Our results reveal a strong well-width dependence of the critical density $n_C$ and ratio between the Zeeman energy ($E_Z$) normalized to the Coulomb energy ($e^2/4\pi\epsilon l_B$), above which a certain FQH state becomes spin polarized. For example, the $\nu=7/5$ FQH state becomes spin polarized at about 3 times higher density or 1.7 times larger $E_Z$ in the 31-nm-wide QW than in the 65-nm-wide QW. This well-width dependence of the spin polarization stems from by the finite electron layer thickness in these QWs and the resulting softening of the Coulomb interaction.

*We acknowledge support through the DOE BES (DE-FG02-00-ER45841) for measurements, and the Gordon and Betty Moore Foundation (Grant GBMF2719), Keck Foundation, and the NSF (DMR-0904117, DMR-1305691 and MRSEC DMR-0819860) for sample fabrication. Work at Arg

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Authors

  • Mansour Shayegan

    • Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
    • Princeton Univ

  • Yang Liu

    • Princeton Univ
    • Princeton University

  • Sukret Hasdemir

    • Princeton Univ
    • Princeton University

  • L.N. Pfeiffer

    • Princeton University
    • Princeton Univ
    • Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
    • Department of Electrical Engineering, Princeton University

  • K.W. West

    • Princeton University
    • Princeton Univ
    • Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA

  • Kirk Baldwin

    • Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
    • Princeton Univ
    • Princeton University