Enhanced Kondo effect via tuned orbital degeneracy in a spin 1/2 artificial atom

S. Sasaki; S. Amaha; N. Asakawa; M. Eto; S. Tarucha

doi:10.1103/PhysRevLett.93.017205

Enhanced Kondo effect via tuned orbital degeneracy in a spin 1/2 artificial atom

S. Sasaki, S. Amaha, N. Asakawa, M. Eto, S. Tarucha

Department of Physics

Research output: Contribution to journal › Article › peer-review

114 Citations (Scopus)

Abstract

A strong Kondo effect in vertical quantum dot holding an odd number of electrons and spin 1/2 was investigated. The estimated Kondo temperature for 'doublet-doublet' degeneracy was found to be similar to that for singlet-triplet degeneracy with an even electron number, indicating that a total of fourfold spin and orbital degeneracy accounts for enhancement of the Kondo temperature. An orbital degeneracy for odd N and S = 1/2 dramatically enhanced the Kondo effect. The results show that an SU(4) model at orbital degeneracy is used to qualitatively reproduce experimental observation.

Original language	English
Article number	017205
Pages (from-to)	017205-1-017205-4
Journal	Physical review letters
Volume	93
Issue number	1
DOIs	https://doi.org/10.1103/PhysRevLett.93.017205
Publication status	Published - 2004 Jul 2

ASJC Scopus subject areas

Physics and Astronomy(all)

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10.1103/PhysRevLett.93.017205

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title = "Enhanced Kondo effect via tuned orbital degeneracy in a spin 1/2 artificial atom",

abstract = "A strong Kondo effect in vertical quantum dot holding an odd number of electrons and spin 1/2 was investigated. The estimated Kondo temperature for 'doublet-doublet' degeneracy was found to be similar to that for singlet-triplet degeneracy with an even electron number, indicating that a total of fourfold spin and orbital degeneracy accounts for enhancement of the Kondo temperature. An orbital degeneracy for odd N and S = 1/2 dramatically enhanced the Kondo effect. The results show that an SU(4) model at orbital degeneracy is used to qualitatively reproduce experimental observation.",

author = "S. Sasaki and S. Amaha and N. Asakawa and M. Eto and S. Tarucha",

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AU - Amaha, S.

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AU - Eto, M.

AU - Tarucha, S.

N1 - Funding Information: The authors acknowledge valuable discussions with ?>T. Sato, W. Izumida, L. I. Glazman, H. Hyuga, ?>M. Stopa, and J. Kondo. The work is supported by the financial support from the Grant-in-Aid for Scientific Research A (Grant No. 40302799), the Nano-Photonic and Electron Devices Technology Project, the Focused Research and Development Project for the Realization of the World’s Most Advanced IT Nation, and SORST-JST.

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AB - A strong Kondo effect in vertical quantum dot holding an odd number of electrons and spin 1/2 was investigated. The estimated Kondo temperature for 'doublet-doublet' degeneracy was found to be similar to that for singlet-triplet degeneracy with an even electron number, indicating that a total of fourfold spin and orbital degeneracy accounts for enhancement of the Kondo temperature. An orbital degeneracy for odd N and S = 1/2 dramatically enhanced the Kondo effect. The results show that an SU(4) model at orbital degeneracy is used to qualitatively reproduce experimental observation.

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Enhanced Kondo effect via tuned orbital degeneracy in a spin 1/2 artificial atom

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