TY - JOUR
T1 - Numerical renormalization group studies of SU(4) Kondo effect in quantum dots
AU - Sato, Tomoya
AU - Eto, Mikio
N1 - Funding Information:
The authors gratefully acknowledge valuable discussions with O. Sakai. This work was partially supported by a Grant-in-Aid for Scientific Research in Priority Areas “Semiconductor Nanospintronics” (No. 14076216) of Ministry of Education, Culture, Sports, Science and Technology, Japan.
PY - 2005/11
Y1 - 2005/11
N2 - We theoretically study an enhancement of the Kondo effect in quantum dots with two orbitals and spin 12. The Kondo temperature and conductance are evaluated as functions of energy difference Δ between the orbitals, using the numerical renormalization group method. The Kondo temperature is maximal around the degeneracy point (Δ=0) and decreases with increasing |Δ| following a power law, TK(Δ)=TK(0)(TK(0)/|Δ|)γ, which is consistent with the scaling analysis. The conductance at T=0 is almost constant 2e2/h. Both the orbitals contribute to the conductance around Δ=0, whereas the current through the upper orbital is negligibly small when |Δ|≳TK(0). These are characteristics of SU(4) Kondo effect.
AB - We theoretically study an enhancement of the Kondo effect in quantum dots with two orbitals and spin 12. The Kondo temperature and conductance are evaluated as functions of energy difference Δ between the orbitals, using the numerical renormalization group method. The Kondo temperature is maximal around the degeneracy point (Δ=0) and decreases with increasing |Δ| following a power law, TK(Δ)=TK(0)(TK(0)/|Δ|)γ, which is consistent with the scaling analysis. The conductance at T=0 is almost constant 2e2/h. Both the orbitals contribute to the conductance around Δ=0, whereas the current through the upper orbital is negligibly small when |Δ|≳TK(0). These are characteristics of SU(4) Kondo effect.
KW - Kondo effect
KW - Numerical renormalization group
KW - Quantum dot
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U2 - 10.1016/j.physe.2005.06.048
DO - 10.1016/j.physe.2005.06.048
M3 - Article
AN - SCOPUS:26944503438
SN - 1386-9477
VL - 29
SP - 652
EP - 655
JO - Physica E: Low-Dimensional Systems and Nanostructures
JF - Physica E: Low-Dimensional Systems and Nanostructures
IS - 3-4
ER -