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Spin textures, screening and excitations in dirty quantum Hall ferromagnets

S. Rapsch·J. T. Chalker·D. K. K. Lee
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Abstract

We study quantum Hall ferromagnets in the presence of a random electrostatic impurity potential. Describing these systems with a classical non-linear sigma model and using analytical estimates supported by results from numerical simulations, we examine the nature of the ground state as a function of disorder strength, $Δ$, and deviation, $δν$, of the average Landau level filling factor from unity. Screening of an impurity potential requires distortions of the spin configuration, and in the absence of Zeeman coupling there is a disorder-driven, zero-temperature phase transition from a ferromagnet at small $Δ$ and $|δν|$ to a spin glass at larger $Δ$ or $|δν|$. We examine ground-state response functions and excitations.

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S. Rapsch, J. T. Chalker, D. K. K. Lee. 2001-09-18. Spin textures, screening and excitations in dirty quantum Hall ferromagnets. https://doi.org/10.1103/physrevlett.88.036801

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