Kondo Impurity in a Mesoscopic Ring: Charge Persistent Current

H. P. Eckle, H. Johannesson, C. A. Stafford

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

We study the influence of a magnetic impurity or ultrasmall quantum dot on the charge persistent current of a mesoscopic ring. The system consists of electrons in a one-dimensional ring threaded by spin-dependent Aharonov-Bohm/Casher fluxes, coupled via an antiferromagnetic exchange interaction to a localized electron. By passing to a basis of electron states with definite parities, the problem is mapped onto a Kondo model for the even-parity channel plus free electrons in the odd-parity channel. The twisted boundary conditions representing the fluxes couple states of opposite parity unless the twist angles satisfy φα = fαπ, where fα are integers, with spin index α = ↑, ↓. For these special values of φα, the model is solved exactly by a Bethe ansatz. Special cases are investigated in detail. In particular we show that the charge stiffness in the case φ = φ is insensitive to the presence of the magnetic impurity/quantum dot.

Original languageEnglish (US)
Pages (from-to)475-483
Number of pages9
JournalJournal of Low Temperature Physics
Volume118
Issue number5-6
StatePublished - Dec 1 2000

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)
  • Condensed Matter Physics

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