Measurement of valley splitting in high-symmetry Si/SiGe quantum dots

2010/12/31 by Matthew G. Borselli, M. G. Borselli, R. S. Ross +27 · 3 citations
Materials Science · Physics and Astronomy · #Degeneracy (biology) #Ground state #Quantum #Quantum and electron transport phenomena #Quantum dot #Quantum dot laser #Semiconductor Quantum Structures and Devices #Shell (structure) #Silicon Nanostructures and Photoluminescence #Singlet state #Symmetry (geometry) #cond-mat.mes-hall

paper · pdf · doi:10.1063/1.3569717

published as Appl. Phys. Lett. 98, 123118 (2011) · 3 pages, 3 figures

openalex publication_date 2011/03/21 · arxiv created 2011/04/13 · arxiv updated 2011/04/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We have demonstrated few-electron quantum dots in Si/SiGe and InGaAs, with occupation number controllable from N=0. These display a high degree of spatial symmetry and identifiable shell structure. Magnetospectroscopy measurements show that two Si-based devices possess a singlet N=2 ground state at low magnetic field, and therefore, the twofold valley degeneracy is lifted. The valley splittings in these two devices were 270 and 120 μeV, suggesting the presence of atomically sharp interfaces in our heterostructures.

Citations

• Valley splitting in a Si/SiGe quantum point contact
• Electronic structure of quantum dots
• Electronic states in silicon quantum dots: Multivalley artificial atoms
• Spins in few-electron quantum dots

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