Analytical expression of Kondo temperature in quantum dot embedded in Aharonov-Bohm ring

Ryosuke Yoshii, Mikio Eto

Research output: Contribution to journalArticle

Abstract

We theoretically study the Kondo effect in a quantum dot embedded in an Aharonov-Bohm ring, using the "poor man's" scaling method. Analytical expressions of the Kondo temperature T K are given as a function of magnetic flux F penetrating the ring. In this Kondo problem, there are two characteristic lengths, L c = h{stroke}v fF/{pipe}ε̃0{pipe} and L K = h{stroke}v F = T K, where v F is the Fermi velocity and ε0 is the renormalized energy level in the quantum dot. The former is the screening length of the charge fluctuation and the latter is that of the spin fluctuation, i.e., size of Kondo screening cloud. We obtain diferent expressions of T K(F) for (i) L c ≪ L K ≪ L, (ii) L c ≪ L ≪ L K, and (iii) L ≪ L c ≪ L K, where L is the size of the ring. T K is remarkably modulated by F in cases (ii) and (iii), whereas it hardly depends on F in case (i). PACS numbers:.

Original languageEnglish
Article number604
Pages (from-to)1-6
Number of pages6
JournalNanoscale Research Letters
Volume6
DOIs
Publication statusPublished - 2011

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Semiconductor quantum dots
Screening
quantum dots
Pipe
Kondo effect
strokes
Picture archiving and communication systems
Spin fluctuations
rings
Magnetic flux
screening
Electron energy levels
Temperature
temperature
magnetic flux
energy levels
scaling

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

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Analytical expression of Kondo temperature in quantum dot embedded in Aharonov-Bohm ring. / Yoshii, Ryosuke; Eto, Mikio.

In: Nanoscale Research Letters, Vol. 6, 604, 2011, p. 1-6.

Research output: Contribution to journalArticle

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N2 - We theoretically study the Kondo effect in a quantum dot embedded in an Aharonov-Bohm ring, using the "poor man's" scaling method. Analytical expressions of the Kondo temperature T K are given as a function of magnetic flux F penetrating the ring. In this Kondo problem, there are two characteristic lengths, L c = h{stroke}v fF/{pipe}ε̃0{pipe} and L K = h{stroke}v F = T K, where v F is the Fermi velocity and ε0 is the renormalized energy level in the quantum dot. The former is the screening length of the charge fluctuation and the latter is that of the spin fluctuation, i.e., size of Kondo screening cloud. We obtain diferent expressions of T K(F) for (i) L c ≪ L K ≪ L, (ii) L c ≪ L ≪ L K, and (iii) L ≪ L c ≪ L K, where L is the size of the ring. T K is remarkably modulated by F in cases (ii) and (iii), whereas it hardly depends on F in case (i). PACS numbers:.

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