6533b7dbfe1ef96bd126ff18

RESEARCH PRODUCT

Pfaffian and fragmented states atν=52in quantum Hall droplets

Ari HarjuHenri SaarikoskiEero TölöEsa RäsänenEsa Räsänen

subject

PhysicsCondensed matter physicsQuantum point contactMacroscopic quantum phenomenaQuantum Hall effectCondensed Matter::Mesoscopic Systems and Quantum Hall EffectCondensed Matter PhysicsElectronic Optical and Magnetic Materialssymbols.namesakePauli exclusion principleQuantum spin Hall effectQuantum mechanicsComposite fermionPrincipal quantum numberFractional quantum Hall effectsymbols

description

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 v=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 quasiparticle characteristics of the v=5/2 quantum Hall state.

https://doi.org/10.1103/physrevb.78.195321