Signatures of Valley Kondo Effect in Si/SiGe Quantum Dots
arXiv:1212.0918 · doi:10.1103/PhysRevB.90.035302
Abstract
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.
16 pages, 7 figures
References in corpus (10)
- Silicon Quantum Electronics
- Orbital Kondo effect in carbon nanotubes
- Coherent Quantum Oscillations in a Silicon Charge Qubit
- Electron spin resonance and spin-valley physics in a silicon double quantum dot
- Magnetic field dependence of valley splitting in realistic Si/SiGe quantum wells
- Disorder-induced valley-orbit hybrid states in Si quantum dots
- Fast tunnel rates in Si/SiGe one-electron single and double quantum dots
- Coulomb blockade and Kondo effect in a few-electron silicon/silicon-germanium quantum dot
- Coulomb interaction and valley-orbit coupling in Si quantum dots
- Si/SiGe quantum dot with superconducting single-electron transistor charge sensor