Morphing of two-dimensional hole systems at $\ensuremath{\nu}=3/2$ in parallel magnetic fields: Compressible, stripe, and fractional quantum Hall phases

Morphing of two-dimensional hole systems at $ν = 3 / 2$ in parallel magnetic fields: Compressible, stripe, and fractional quantum Hall phases

Yang Liu, M. A. Mueed, Md. Shafayat Hossain, S. Hasdermir, L. N. Pfeiffer, K. W. West, K. W. Baldwin, and M. Shayegan

Phys. Rev. B 94, 155312 – Published 31 October 2016

Abstract

A transport study of two-dimensional (2D) holes confined to wide GaAs quantum wells provides a glimpse of a subtle competition between different many-body phases at a Landau level filling $ν = 3 / 2$ in tilted magnetic fields. At large tilt angles ( $θ$ ), an anisotropic, stripe (or nematic) phase replaces the isotropic compressible Fermi sea at $ν = 3 / 2$ if the quantum well has a symmetric charge distribution. When the charge distribution is made asymmetric, instead of the stripe phase, an even-denominator fractional quantum state appears at $ν = 3 / 2$ in a range of large $θ$ , and reverts back to a compressible state at even higher $θ$ . We attribute this remarkable evolution to the significant mixing of the excited and ground-state Landau levels of 2D hole systems in tilted fields.