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

Roddaro, Stefano LU ; Fuhrer, Andreas LU ; Brusheim, Patrik LU ; Fasth, Carina LU ; Xu, Hongqi LU ; Samuelson, Lars LU ; Xiang, J and Lieber, C M (2008) In Physical Review Letters 101(18).
Abstract
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... (More)
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. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Letters
volume
101
issue
18
publisher
American Physical Society
external identifiers
  • wos:000260574600051
  • pmid:18999847
  • scopus:55149088149
ISSN
1079-7114
DOI
10.1103/PhysRevLett.101.186802
language
English
LU publication?
yes
id
d4225370-708d-4e91-ab62-6dbc9fc6a34b (old id 1271623)
date added to LUP
2009-02-06 16:34:37
date last changed
2017-05-07 03:36:02
@article{d4225370-708d-4e91-ab62-6dbc9fc6a34b,
  abstract     = {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.},
  articleno    = {186802},
  author       = {Roddaro, Stefano and Fuhrer, Andreas and Brusheim, Patrik and Fasth, Carina and Xu, Hongqi and Samuelson, Lars and Xiang, J and Lieber, C M},
  issn         = {1079-7114},
  language     = {eng},
  number       = {18},
  publisher    = {American Physical Society},
  series       = {Physical Review Letters},
  title        = {Spin States of holes in ge/si nanowire quantum dots.},
  url          = {http://dx.doi.org/10.1103/PhysRevLett.101.186802},
  volume       = {101},
  year         = {2008},
}