The conductance of strongly confined one-dimensional constrictions fabricated from Si/SiGe two-dimensional electron gases is investigated. Conductance measurements reveal conductance quantization in units of G0 =2 e2 /h rather than 2 G0 =4 e2 /h, as expected in the presence of valley and spin degeneracy. Furthermore, at temperatures below T=400 mK, small steps and peaklike 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.

Conductance and valley splitting in etched Si/SiGe one-dimensional nanostructures

BELTRAM, Fabio
2010

Abstract

The conductance of strongly confined one-dimensional constrictions fabricated from Si/SiGe two-dimensional electron gases is investigated. Conductance measurements reveal conductance quantization in units of G0 =2 e2 /h rather than 2 G0 =4 e2 /h, as expected in the presence of valley and spin degeneracy. Furthermore, at temperatures below T=400 mK, small steps and peaklike 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.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11384/5936
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 9
social impact