Abstract
We investigate the Kondo effect in a quantum dot with almost degenerate spin-singlet and triplet states for an even number of electrons. We show that the Kondo temperature as a function of the energy difference between the states reaches its maximum around and decreases with increasing . The Kondo effect is thus enhanced by competition between singlet and triplet states. Our results explain recent experimental findings. We evaluate the linear conductance in the perturbative regime.
- Received 31 January 2000
DOI:https://doi.org/10.1103/PhysRevLett.85.1306
©2000 American Physical Society