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Spectroscopy and level detuning of few-electron spin states in parallel InAs quantum dots

Thelander, Claes LU ; Nilsson, Malin LU ; Viñas Boström, Florinda LU ; Burke, Adam LU ; Lehmann, Sebastian LU ; Dick, Kimberly A. LU and Leijnse, Martin LU (2018) In Physical Review B 98(24).
Abstract

We use tunneling spectroscopy to study the evolution of few-electron spin states in parallel InAs nanowire double quantum dots (QDs) as a function of level detuning and applied magnetic field. Compared to the much more studied serial configuration, parallel coupling of the QDs to source and drain greatly expands the probing range of excited-state transport. Owing to a strong confinement, we can here isolate transport involving only the very first interacting single QD orbital pair. For the (2,0)-(1,1) charge transition, with relevance for spin-based qubits, we investigate the excited (1,1) triplet, and hybridization of the (2,0) and (1,1) singlets. An applied magnetic field splits the (1,1) triplet, and due to spin-orbit induced mixing... (More)

We use tunneling spectroscopy to study the evolution of few-electron spin states in parallel InAs nanowire double quantum dots (QDs) as a function of level detuning and applied magnetic field. Compared to the much more studied serial configuration, parallel coupling of the QDs to source and drain greatly expands the probing range of excited-state transport. Owing to a strong confinement, we can here isolate transport involving only the very first interacting single QD orbital pair. For the (2,0)-(1,1) charge transition, with relevance for spin-based qubits, we investigate the excited (1,1) triplet, and hybridization of the (2,0) and (1,1) singlets. An applied magnetic field splits the (1,1) triplet, and due to spin-orbit induced mixing with the (2,0) singlet we clearly resolve transport through all triplet states near the avoided singlet-triplet crossings. Transport calculations, based on a simple model with one orbital on each QD, fully replicate the experimental data. Finally, we observe an expected mirrored symmetry between the one- to two-electron and two- to three-electron transitions resulting from the twofold spin degeneracy of the orbitals.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
98
issue
24
publisher
American Physical Society
external identifiers
  • scopus:85058310282
ISSN
2469-9950
DOI
10.1103/PhysRevB.98.245305
language
English
LU publication?
yes
id
7f057b5a-a1f7-44fe-8757-48dc3c3df97a
date added to LUP
2019-01-03 12:58:27
date last changed
2019-02-20 11:41:25
@article{7f057b5a-a1f7-44fe-8757-48dc3c3df97a,
  abstract     = {<p>We use tunneling spectroscopy to study the evolution of few-electron spin states in parallel InAs nanowire double quantum dots (QDs) as a function of level detuning and applied magnetic field. Compared to the much more studied serial configuration, parallel coupling of the QDs to source and drain greatly expands the probing range of excited-state transport. Owing to a strong confinement, we can here isolate transport involving only the very first interacting single QD orbital pair. For the (2,0)-(1,1) charge transition, with relevance for spin-based qubits, we investigate the excited (1,1) triplet, and hybridization of the (2,0) and (1,1) singlets. An applied magnetic field splits the (1,1) triplet, and due to spin-orbit induced mixing with the (2,0) singlet we clearly resolve transport through all triplet states near the avoided singlet-triplet crossings. Transport calculations, based on a simple model with one orbital on each QD, fully replicate the experimental data. Finally, we observe an expected mirrored symmetry between the one- to two-electron and two- to three-electron transitions resulting from the twofold spin degeneracy of the orbitals.</p>},
  articleno    = {245305},
  author       = {Thelander, Claes and Nilsson, Malin and Viñas Boström, Florinda and Burke, Adam and Lehmann, Sebastian and Dick, Kimberly A. and Leijnse, Martin},
  issn         = {2469-9950},
  language     = {eng},
  month        = {12},
  number       = {24},
  publisher    = {American Physical Society},
  series       = {Physical Review B},
  title        = {Spectroscopy and level detuning of few-electron spin states in parallel InAs quantum dots},
  url          = {http://dx.doi.org/10.1103/PhysRevB.98.245305},
  volume       = {98},
  year         = {2018},
}