Mingyun Yuan, Zhen Yang, Chunyang Tang, A. J. Rimberg, R. Joynt, D. E. Savage, M. G. Lagally, M. A. Eriksson
We report measurement of the valley Kondo effect in a Si/SiGe quantum dot. The Kondo peaks in two consecutive Coulomb diamonds show unusual behavior in a magnetic field that we interpret as arising from the valley degree of freedom. In one diamond two Kondo peaks due to screening of the valley index exist at zero field, revealing a zero-field valley splitting of 0.28 meV. In a finite field the peaks broaden and coalesce due to Zeeman splitting. In the other diamond, a single resonance persists at zero bias for non-zero field, a phenomenon characteristic of valley non-conservation in tunneling.
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http://arxiv.org/abs/1212.0918
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