Composite fermions in bands with N -fold rotational symmetry

Matteo Ippoliti, Scott D. Geraedts, R. N. Bhatt

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12 Scopus citations


We study the effect of band anisotropy with discrete rotational symmetry CN (where N≥2) in the quantum Hall regime of two-dimensional electron systems. We focus on the composite Fermi liquid (CFL) at half-filling of the lowest Landau level. We find that the magnitude of anisotropy transferred to the composite fermions decreases very rapidly with N. We demonstrate this by performing density matrix normalization group calculations on the CFL, and comparing the anisotropy of the composite fermion Fermi contour with that of the (noninteracting) electron Fermi contour at zero magnetic field. We also show that the effective interaction between the electrons after projecting into a single Landau level is much less anisotropic than the band, a fact which does not depend on filling and thus has implications for other quantum Hall states as well. Our results confirm experimental observations on anisotropic bands with warped Fermi contours, where the only detectable effect on the composite Fermi contour is an elliptical distortion (N=2).

Original languageEnglish (US)
Article number115151
JournalPhysical Review B
Issue number11
StatePublished - Sep 25 2017

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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