Singlet-Triplet Transition in lateral Quantum Dots: A Numerical Renormalization Group Study
Abstract
We discuss transport through a lateral quantum dot in the vicinity of a singlet-triplet spin transition in its ground state. Extracting the scattering phase shifts from the numerical renormalization group spectra, we determine the linear conductance at zero temperature as a function of a Zeeman field and the splitting of the singlet and triplet states. We find reduced low-energy transport, and a non-monotonic magnetic field dependence both in the singlet and the triplet regime. For a generic set of dot parameters and no Zeeman splitting, the singlet-triplet transition may be identified with the conductance maximum. The conductance is least sensitive to the magnetic field in the region of the transition, where it decreases upon application of a magnetic field. Our results are in good agreement with recent experimental data.
Cite
@article{arxiv.cond-mat/0306418,
title = {Singlet-Triplet Transition in lateral Quantum Dots: A Numerical Renormalization Group Study},
author = {W. Hofstetter and G. Zarand},
journal= {arXiv preprint arXiv:cond-mat/0306418},
year = {2009}
}
Comments
9 pages Revtex, 10 eps figures