Spin-pairing instabilities at the coincidence of two Landau levels

Abstract

The effect of interactions near the coincidence of two Landau levels with opposite spins at filling factor 1/2 is investigated. By mapping to Composite Fermions it is shown that the fluctuations of the gauge field induces an effective attractive Fermion interaction. This can lead to a spin-singlet ground state that is separated from the excited states by a gap. The magnitude of the gap is evaluated. The results are consistent with the recently observed half-polarized states in the FQHE at a fixed filling factor. It is suggested that similar anomalies exist for other spin configurations in degenerate spin-up and spin-down Landau levels. An experiment for testing the spin-singlet state is proposed.

arXiv commentto be published in Physical Review B

References in corpus (8)

• Evidence for a Goldstone Mode in a Double Layer Quantum Hall System
• Gauge Fields and Pairing in Double-Layer Composite Fermion Metals
• Josephson Effect Without Superconductivity: Realization in Quantum Hall Bilayers
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• Theory of the Half-Polarized Quantum Hall States
• A Composite Fermion Hofstader Problem: Partially Polarized Density Wave States in the 2/5 FQHE

Cited by in corpus (8)

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• Domain Formation in v=2/3 Fractional Quantum Hall Systems
• Specific Heat of a Fractional Quantum Hall System
• Integral and fractional Quantum Hall Ising ferromagnets
• On ground states of interacting Composite Fermions with spin at half filling
• Spin in fractional quantum Hall systems
• Electron conductivity and second generation Composite Fermions