Spin States of holes in ge/si nanowire quantum dots.

Summary, in English

We investigate tunable hole quantum dots defined by surface gating Ge/Si core-shell nanowire heterostructures. In single level Coulomb-blockade transport measurements at low temperatures spin doublets are found, which become sequentially filled by holes. Magnetotransport measurements allow us to extract a g factor g;{*} approximately 2 close to the value of a free spin-1/2 particle in the case of the smallest dot. In less confined quantum dots smaller g factor values are observed. This indicates a lifting of the expected strong spin-orbit interaction effects in the valence band for holes confined in small enough quantum dots. By comparing the excitation spectrum with the addition spectrum we tentatively identify a hole exchange interaction strength chi approximately 130 mueV.

• Författare: Stefano Roddaro; Andreas Fuhrer; Patrik Brusheim; Carina Fasth; Hongqi Xu; Lars Samuelson; J Xiang; C M Lieber
• Avdelning/ar: Fasta tillståndets fysik
• Publiceringsår: 2008
• Språk: Engelska
• Publikation/Tidskrift/Serie: Physical Review Letters
• Volym: 101
• Issue: 18
• Länkar: http://dx.doi.org/10.1103/PhysRevLett.101.186802
• Dokumenttyp: Artikel i tidskrift
• Förlag: American Physical Society
• Ämne: Condensed Matter Physics
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1079-7114