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Individually addressable double quantum dots formed with nanowire polytypes and identified by epitaxial markers

Barker, D. LU ; Lehmann, S. LU ; Namazi, L. LU ; Nilsson, M. LU ; Thelander, C. LU ; Dick, K. A. LU and Maisi, V. F. LU (2019) In Applied Physics Letters 114(18).
Abstract

Double quantum dots (DQDs) hold great promise as building blocks for quantum technology as they allow for two electronic states to coherently couple. Defining QDs with materials rather than using electrostatic gating allows for QDs with a hard-wall confinement potential and more robust charge and spin states. An unresolved problem is how to individually address these QDs, which is necessary for controlling quantum states. We here report the fabrication of DQD devices defined by the conduction band edge offset at the interface of the wurtzite and zinc blende crystal phases of InAs in nanowires. By using sacrificial epitaxial GaSb markers selectively forming on one crystal phase, we are able to precisely align gate electrodes allowing us... (More)

Double quantum dots (DQDs) hold great promise as building blocks for quantum technology as they allow for two electronic states to coherently couple. Defining QDs with materials rather than using electrostatic gating allows for QDs with a hard-wall confinement potential and more robust charge and spin states. An unresolved problem is how to individually address these QDs, which is necessary for controlling quantum states. We here report the fabrication of DQD devices defined by the conduction band edge offset at the interface of the wurtzite and zinc blende crystal phases of InAs in nanowires. By using sacrificial epitaxial GaSb markers selectively forming on one crystal phase, we are able to precisely align gate electrodes allowing us to probe and control each QD independently. We hence observe textbooklike charge stability diagrams, a discrete energy spectrum, and electron numbers consistent with theoretical estimates and investigate the tunability of the devices, finding that changing the electron number can be used to tune the tunnel barrier as expected by simple band diagram arguments.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Applied Physics Letters
volume
114
issue
18
article number
183502
publisher
American Institute of Physics (AIP)
external identifiers
  • scopus:85065465375
ISSN
0003-6951
DOI
10.1063/1.5089275
language
English
LU publication?
yes
id
7b31c2f8-c3a6-4c8b-b8f9-390820847c9b
date added to LUP
2019-05-22 14:15:42
date last changed
2023-11-18 23:32:50
@article{7b31c2f8-c3a6-4c8b-b8f9-390820847c9b,
  abstract     = {{<p>Double quantum dots (DQDs) hold great promise as building blocks for quantum technology as they allow for two electronic states to coherently couple. Defining QDs with materials rather than using electrostatic gating allows for QDs with a hard-wall confinement potential and more robust charge and spin states. An unresolved problem is how to individually address these QDs, which is necessary for controlling quantum states. We here report the fabrication of DQD devices defined by the conduction band edge offset at the interface of the wurtzite and zinc blende crystal phases of InAs in nanowires. By using sacrificial epitaxial GaSb markers selectively forming on one crystal phase, we are able to precisely align gate electrodes allowing us to probe and control each QD independently. We hence observe textbooklike charge stability diagrams, a discrete energy spectrum, and electron numbers consistent with theoretical estimates and investigate the tunability of the devices, finding that changing the electron number can be used to tune the tunnel barrier as expected by simple band diagram arguments.</p>}},
  author       = {{Barker, D. and Lehmann, S. and Namazi, L. and Nilsson, M. and Thelander, C. and Dick, K. A. and Maisi, V. F.}},
  issn         = {{0003-6951}},
  language     = {{eng}},
  number       = {{18}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Applied Physics Letters}},
  title        = {{Individually addressable double quantum dots formed with nanowire polytypes and identified by epitaxial markers}},
  url          = {{http://dx.doi.org/10.1063/1.5089275}},
  doi          = {{10.1063/1.5089275}},
  volume       = {{114}},
  year         = {{2019}},
}