We report measurements consistent with the valley Kondo effect in Si/SiGe quantum dots, evidenced by peaks in the conductance versus source-drain voltage that show strong temperature dependence. The Kondo peaks show unusual behavior in a magnetic field that we interpret as arising from the valley degree of freedom. The interplay of valley and Zeeman splittings is suggested by the presence of side peaks, revealing a zero-field valley splitting between 0.28 to 0.34 meV. A zero-bias conductance peak for non-zero magnetic field, a phenomenon consistent with valley non- conservation in tunneling, is observed in two samples.
@article{arxiv.1212.0918,
title = {Signatures of Valley Kondo Effect in Si/SiGe Quantum Dots},
author = {Mingyun Yuan and R. Joynt and Zhen Yang and Chunyang Tang and D. E. Savage and M. G. Lagally and M. A. Eriksson and A. J. Rimberg},
journal= {arXiv preprint arXiv:1212.0918},
year = {2014}
}