Electrostatics of Edge States of Quantum Hall Systems with Constrictions: Metal--Insulator Transition Tuned by External Gates

dc.creatorPapa, Emiliano
dc.creatorStroh, Tilo
dc.date2006-07-18
dc.date2007-01-07
dc.date.accessioned2026-07-07T07:42:57Z
dc.date.available2026-07-07T07:42:57Z
dc.descriptionThe nature of a metal--insulator transition tuned by external gates in quantum Hall (QH) systems with point constrictions at integer bulk filling, as reported in recent experiments of Roddaro et al. [1], is addressed. We are particularly concerned here with the insulating behavior--the phenomena of backscattering enhancement induced at high gate voltages. Electrostatics calculations for QH systems with split gates performed here show that observations are not a consequence of interedge interactions near the point contact. We attribute the phenomena of backscattering enhancement to a splitting of the integer edge into conducting and insulating stripes, which enable the occurrence of the more relevant backscattering processes of fractionally charged quasiparticles at the point contact. For the values of the parameters used in the experiments we find that the conducting channels are widely separated by the insulating stripes and that their presence alters significantly the low-energy dynamics of the edges. Interchannel impurity scattering does not influence strongly the tunneling exponents as they are found to be irrelevant processes at low energies. Exponents of backscattering at the point contact are unaffected by interchannel Coulomb interactions since all channels have same chirality of propagation.
dc.description19 pages; To appear in Phys. Rev. B
dc.identifierhttps://arxiv.org/abs/cond-mat/0607458
dc.identifierhttp://arxiv.org/abs/cond-mat/0607458
dc.identifierPhys. Rev. B 75, 045342 (2007)
dc.identifierdoi:10.1103/PhysRevB.75.045342
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/122640
dc.subjectMesoscale and Nanoscale Physics
dc.subjectStrongly Correlated Electrons
dc.titleElectrostatics of Edge States of Quantum Hall Systems with Constrictions: Metal--Insulator Transition Tuned by External Gates
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