TY - GEN

T1 - SU(4) Kondo effect in quantum dots with two orbitals and spin 1/2

AU - Eto, Mikio

PY - 2005/6/30

Y1 - 2005/6/30

N2 - We theoretically study the Kondo effect in quantum dots with two orbitals and spin 1/2. The Kondo temperature TK is evaluated, as a function of energy difference Δ between the orbitals, using the scaling method. TK is maximal around the degeneracy point (Δ = 0) and decreases with increasing Δ following a power law, TK(Δ) = T K(0) (TK(0)/Δ)γ, which is understood as a crossover from SU(4) to SU(2) Kondo effect. The exponents on both sides of a level crossing, γL and γR, satisfy a relation of γL γR = 1. We compare this enhanced Kondo effect with that at the spin-singlet-triplet degeneracy for an even number of electrons, to explain recent experimental results.

AB - We theoretically study the Kondo effect in quantum dots with two orbitals and spin 1/2. The Kondo temperature TK is evaluated, as a function of energy difference Δ between the orbitals, using the scaling method. TK is maximal around the degeneracy point (Δ = 0) and decreases with increasing Δ following a power law, TK(Δ) = T K(0) (TK(0)/Δ)γ, which is understood as a crossover from SU(4) to SU(2) Kondo effect. The exponents on both sides of a level crossing, γL and γR, satisfy a relation of γL γR = 1. We compare this enhanced Kondo effect with that at the spin-singlet-triplet degeneracy for an even number of electrons, to explain recent experimental results.

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UR - http://www.scopus.com/inward/citedby.url?scp=33749487903&partnerID=8YFLogxK

U2 - 10.1063/1.1994359

DO - 10.1063/1.1994359

M3 - Conference contribution

AN - SCOPUS:33749487903

SN - 0735402574

SN - 9780735402577

T3 - AIP Conference Proceedings

SP - 821

EP - 822

BT - PHYSICS OF SEMICONDUCTORS

T2 - PHYSICS OF SEMICONDUCTORS: 27th International Conference on the Physics of Semiconductors, ICPS-27

Y2 - 26 July 2004 through 30 July 2004

ER -