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Direct Measurement of the Spin-Orbit Interaction in a Two-Electron InAs Nanowire Quantum Dot

Fasth, Carina LU ; Fuhrer, Andreas LU ; Samuelson, Lars LU ; Golovach, Vitaly and Loss, Daniel (2007) In Physical Review Letters 98. p.1-266801
Abstract
We demonstrate control of the electron number down to the last electron in tunable few-electron quantum dots defined in catalytically grown InAs nanowires. Using low temperature transport spectroscopy in the Coulomb blockade regime, we propose a method to directly determine the magnitude of the spin-orbit interaction in a two-electron artificial atom with strong spin-orbit coupling. Because of a large effective g factor |g*|=8±1, the transition from a singlet S to a triplet T+ ground state with increasing magnetic field is dominated by the Zeeman energy rather than by orbital effects. We find that the spin-orbit coupling mixes the T+ and S states and thus induces an avoided crossing with magnitude ΔSO=0.25±0.05  meV. This allows us to... (More)
We demonstrate control of the electron number down to the last electron in tunable few-electron quantum dots defined in catalytically grown InAs nanowires. Using low temperature transport spectroscopy in the Coulomb blockade regime, we propose a method to directly determine the magnitude of the spin-orbit interaction in a two-electron artificial atom with strong spin-orbit coupling. Because of a large effective g factor |g*|=8±1, the transition from a singlet S to a triplet T+ ground state with increasing magnetic field is dominated by the Zeeman energy rather than by orbital effects. We find that the spin-orbit coupling mixes the T+ and S states and thus induces an avoided crossing with magnitude ΔSO=0.25±0.05  meV. This allows us to calculate the spin-orbit length λSO≈127  nm in such systems using a simple model. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Letters
volume
98
pages
1 - 266801
publisher
American Physical Society
external identifiers
  • WOS:000247625100048
  • Scopus:34547342695
ISSN
1079-7114
DOI
10.1103/PhysRevLett.98.266801
language
English
LU publication?
yes
id
a14ccdfe-24b2-477e-8275-6a81de3c99c7 (old id 642631)
date added to LUP
2007-12-03 16:27:00
date last changed
2016-11-20 04:28:26
@misc{a14ccdfe-24b2-477e-8275-6a81de3c99c7,
  abstract     = {We demonstrate control of the electron number down to the last electron in tunable few-electron quantum dots defined in catalytically grown InAs nanowires. Using low temperature transport spectroscopy in the Coulomb blockade regime, we propose a method to directly determine the magnitude of the spin-orbit interaction in a two-electron artificial atom with strong spin-orbit coupling. Because of a large effective g factor |g*|=8±1, the transition from a singlet S to a triplet T+ ground state with increasing magnetic field is dominated by the Zeeman energy rather than by orbital effects. We find that the spin-orbit coupling mixes the T+ and S states and thus induces an avoided crossing with magnitude ΔSO=0.25±0.05  meV. This allows us to calculate the spin-orbit length λSO≈127  nm in such systems using a simple model.},
  author       = {Fasth, Carina and Fuhrer, Andreas and Samuelson, Lars and Golovach, Vitaly and Loss, Daniel},
  issn         = {1079-7114},
  language     = {eng},
  pages        = {1--266801},
  publisher    = {ARRAY(0x9719d78)},
  series       = {Physical Review Letters},
  title        = {Direct Measurement of the Spin-Orbit Interaction in a Two-Electron InAs Nanowire Quantum Dot},
  url          = {http://dx.doi.org/10.1103/PhysRevLett.98.266801},
  volume       = {98},
  year         = {2007},
}