Physical Review B - Condensed Matter and Materials Physics
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 nonzero magnetic field, a phenomenon consistent with valley nonconservation in tunneling, is observed in two samples.
Yuan, Mingyun; Joynt, R.; Yang, Zhen; Tang, Chunyang; Savage, D. E.; Lagally, M. G.; Eriksson, M. A.; and Rimberg, A. J., "Signatures of the Valley Kondo Effect in Si/Sige Quantum Dots" (2014). Open Dartmouth: Faculty Open Access Scholarship. 1929.