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Magnetoroton instabilities and static susceptibilities in higher Landau levels

M. O. Goerbig·C. Morais Smith
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Abstract

We present analytical results concerning the magneto-roton instability in higher Landau levels evaluated in the single mode approximation. The roton gap appears at a finite wave vector, which is approximately independent of the LL index n, in agreement with numerical calculations in the composite-fermion picture. However, a large maximum in the static susceptibility indicates a charge density modulation with wave vectors $q_0(n)\sim 1/\sqrt{2n+1}$, as expected from Hartree-Fock predictions. We thus obtain a unified description of the leading charge instabilities in all LLs.

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M. O. Goerbig, C. Morais Smith. 2002-12-18. Magnetoroton instabilities and static susceptibilities in higher Landau levels. https://doi.org/10.1103/physrevb.66.241101

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