Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Coherence of an Electronic Two-Level System under Continuous Charge Sensing by a Quantum Dot Detector

Haldar, Subhomoy LU ; Munk, Morten LU ; Havir, Harald LU ; Khan, Waqar LU ; Lehmann, Sebastian LU ; Thelander, Claes LU ; Dick, Kimberly A. LU ; Samuelsson, Peter LU ; Potts, Patrick P. LU orcid and Maisi, Ville F. LU (2025) In Physical Review Letters 134(2).
Abstract

We investigate experimentally the quantum coherence of an electronic two-level system in a double quantum dot under continuous charge detection. The charge state of the two-level system is monitored by a capacitively coupled single quantum dot detector that imposes a backaction effect on the system. The measured backaction is well described by an additional decoherence rate, approximately linearly proportional to the detector electron tunneling rate. We provide a model for the decoherence rate arising due to level detuning fluctuations induced by detector charge fluctuations. The theory predicts a factor of 2 lower decoherence rates than observed in the experiment, suggesting the need for a more elaborate theory accounting for... (More)

We investigate experimentally the quantum coherence of an electronic two-level system in a double quantum dot under continuous charge detection. The charge state of the two-level system is monitored by a capacitively coupled single quantum dot detector that imposes a backaction effect on the system. The measured backaction is well described by an additional decoherence rate, approximately linearly proportional to the detector electron tunneling rate. We provide a model for the decoherence rate arising due to level detuning fluctuations induced by detector charge fluctuations. The theory predicts a factor of 2 lower decoherence rates than observed in the experiment, suggesting the need for a more elaborate theory accounting for additional sources of decoherence.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Letters
volume
134
issue
2
article number
023601
publisher
American Physical Society
external identifiers
  • pmid:39913833
  • scopus:85215441507
ISSN
0031-9007
DOI
10.1103/PhysRevLett.134.023601
language
English
LU publication?
yes
id
37661fe8-d7af-4fba-a7c7-4ba0c8be80c1
date added to LUP
2025-06-02 09:54:22
date last changed
2025-06-30 12:59:26
@article{37661fe8-d7af-4fba-a7c7-4ba0c8be80c1,
  abstract     = {{<p>We investigate experimentally the quantum coherence of an electronic two-level system in a double quantum dot under continuous charge detection. The charge state of the two-level system is monitored by a capacitively coupled single quantum dot detector that imposes a backaction effect on the system. The measured backaction is well described by an additional decoherence rate, approximately linearly proportional to the detector electron tunneling rate. We provide a model for the decoherence rate arising due to level detuning fluctuations induced by detector charge fluctuations. The theory predicts a factor of 2 lower decoherence rates than observed in the experiment, suggesting the need for a more elaborate theory accounting for additional sources of decoherence.</p>}},
  author       = {{Haldar, Subhomoy and Munk, Morten and Havir, Harald and Khan, Waqar and Lehmann, Sebastian and Thelander, Claes and Dick, Kimberly A. and Samuelsson, Peter and Potts, Patrick P. and Maisi, Ville F.}},
  issn         = {{0031-9007}},
  language     = {{eng}},
  number       = {{2}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review Letters}},
  title        = {{Coherence of an Electronic Two-Level System under Continuous Charge Sensing by a Quantum Dot Detector}},
  url          = {{http://dx.doi.org/10.1103/PhysRevLett.134.023601}},
  doi          = {{10.1103/PhysRevLett.134.023601}},
  volume       = {{134}},
  year         = {{2025}},
}