Quasibound states and evidence for a spin-1 Kondo effect in asymmetric quantum point contacts


Journal Article

Linear conductance below 2e2/h shows resonance peaks in highly asymmetric quantum point contacts (QPCs). As the channel length increases, the number of peaks also increases. At the same time, differential conductance exhibits zero-bias anomalies (ZBAs) in correspondence with every other peak in the linear conductance. This even-odd effect, observable in the longer channels, is consistent with the formation of correlation-induced quasilocalized states within the QPC. In rare cases, triple peaks are observed, indicating the formation of a spin-1 Kondo effect when the electron filling number is even. Changing the gate voltage tunes this spin triplet to a singlet which exhibits no ZBA. The triple peak provides evidence suggestive of a spin singlet-triplet transition in a QPC, and the presence of a ferromagnetic spin interaction between electrons. © 2013 American Physical Society.

Full Text

Duke Authors

Cited Authors

  • Zhang, H; Wu, PM; Chang, AM

Published Date

  • August 22, 2013

Published In

Volume / Issue

  • 88 / 7

Electronic International Standard Serial Number (EISSN)

  • 1550-235X

International Standard Serial Number (ISSN)

  • 1098-0121

Digital Object Identifier (DOI)

  • 10.1103/PhysRevB.88.075311

Citation Source

  • Scopus