Phonon Excitations of Composite Fermion Landau Levels

Abstract

Phonon excitations of fractional quantum Hall states at filling factors nu = 1/3, 2/5, 4/7, 3/5, 4/3, and 5/3 are experimentally shown to be based on Landau level transitions of Composite Fermions. At filling factor nu = 2/3, however, a linear field dependence of the excitation energy in the high-field regime rather hints towards a spin transition excited by the phonons. We propose to explain this surprising observation by an only partially polarized 2/3-ground-state making the energetically lower lying spin transition also allowed for phonon excitations.

arXiv comment4 pages, 3 figures, 1 table, accepted for Phys. Rev. Lett

References in corpus (5)

• Observation of a new phase transition between fully and partially polarized quantum Hall states with charge and spin gaps at $\nu =2/3$
• Phonon Absorption at the Magneto-Roton Minimum in the Fractional Quantum Hall Effect
• Theory of the Half-Polarized Quantum Hall States
• Direct Measurement of the g-Factor of Composite Fermions
• A theory of phonon spectroscopy in the fractional quantum Hall regime