Pfaffian and fragmented states at nu=5/2 in quantum Hall droplets

Abstract

When a gas of electrons is confined to two dimensions, application of a strong magnetic field may lead to startling phenomena such as emergence of electron pairing. According to a theory this manifests itself as appearance of the fractional quantum Hall effect with a quantized conductivity at an unusual half-integer nu=5/2 Landau level filling. Here we show that similar electron pairing may occur in quantum dots where the gas of electrons is trapped by external electric potentials into small quantum Hall droplets. However, we also find theoretical and experimental evidence that, depending on the shape of the external potential, the paired electron state can break down, which leads to a fragmentation of charge and spin densities into incompressible domains. The fragmentation of the quantum Hall states could be an issue in the proposed experiments that aim to probe for non-abelian quasi-particle characteristics of the nu=5/2 quantum Hall state.

9 pages, 8 figures

References in corpus (11)

• Non-Abelian Anyons and Topological Quantum Computation
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• Finite Layer Thickness Stabilizes the Pfaffian State for the 5/2 Fractional Quantum Hall Effect: Wavefunction Overlap and Topological Degeneracy
• Three real-space discretization techniques in electronic structure calculations
• Detecting non-Abelian Statistics with Electronic Mach-Zehnder Interferometer
• Paired composite fermion wavefunctions
• Testing of two-dimensional local approximations in the current-spin and spin-density-functional theories
• Spin-droplets in confined quantum Hall systems
• Half-Integer Filling Factor States in Quantum Dots
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• Probing a Kondo correlated quantum dot with spin spectroscopy

Cited by in corpus (4)

• Semi-local density functional for the exchange-correlation energy of electrons in two dimensions
• Effects of thickness in quantum dots at strong magnetic fields
• Quantum Hall droplet laterally coupled to a quantum ring
• Formation of spin droplet at nu = 5/2 in an asymmetric quantum dot under quantum Hall conditions