The conductance of strongly-confined 1D constrictions fabricated from Si/SiGe two-dimensional electron gases is investigated. Conductance measurements reveal conductance quantization in units of G0 = 2e2/h rather than 2G0 = 4e2/h, as expected in the presence of valley and spin degeneracy. Furthermore, at temperatures below T = 400 mK small steps and peak-like features, superimposed to the conductance plateaus, become visible. The conductance in the presence of parallel and perpendicular magnetic field shows that significant valley splitting is present even at zero magnetic field. The enhanced valley splitting observed in our etched devices is related to the strong in-plane confinement.
G., F., L., D.G., Evangelisti, F., E., G., A., N., V., P., et al. (2010). Conductance and valley splitting in etched Si/SiGe one-dimensional nanostructures. PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS, 81, 195311.
Conductance and valley splitting in etched Si/SiGe one-dimensional nanostructures
EVANGELISTI, Florestano;
2010-01-01
Abstract
The conductance of strongly-confined 1D constrictions fabricated from Si/SiGe two-dimensional electron gases is investigated. Conductance measurements reveal conductance quantization in units of G0 = 2e2/h rather than 2G0 = 4e2/h, as expected in the presence of valley and spin degeneracy. Furthermore, at temperatures below T = 400 mK small steps and peak-like features, superimposed to the conductance plateaus, become visible. The conductance in the presence of parallel and perpendicular magnetic field shows that significant valley splitting is present even at zero magnetic field. The enhanced valley splitting observed in our etched devices is related to the strong in-plane confinement.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
