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Quantum dot source-drain transport response at microwave frequencies

Havir, Harald LU ; Haldar, Subhomoy LU ; Khan, Waqar LU ; Lehmann, Sebastian LU ; Dick, Kimberly A. LU ; Thelander, Claes LU ; Samuelsson, Peter LU and Maisi, Ville F. LU (2023) In Physical Review B 108(20).
Abstract

Quantum dots are frequently used as charge-sensitive devices in low-temperature experiments to probe electric charge in mesoscopic conductors where the current running through the quantum dot is modulated by the nearby charge environment. Recent experiments have operated these detectors using reflectometry measurements up to gigahertz frequencies rather than probing the low-frequency current through the dot. In this work, we use an on-chip coplanar waveguide resonator to measure the source-drain transport response of two quantum dots at a frequency of 6 GHz, further increasing the bandwidth limit for charge detection. Similar to that in the low-frequency domain, the response is here predominantly dissipative. For large tunnel coupling,... (More)

Quantum dots are frequently used as charge-sensitive devices in low-temperature experiments to probe electric charge in mesoscopic conductors where the current running through the quantum dot is modulated by the nearby charge environment. Recent experiments have operated these detectors using reflectometry measurements up to gigahertz frequencies rather than probing the low-frequency current through the dot. In this work, we use an on-chip coplanar waveguide resonator to measure the source-drain transport response of two quantum dots at a frequency of 6 GHz, further increasing the bandwidth limit for charge detection. Similar to that in the low-frequency domain, the response is here predominantly dissipative. For large tunnel coupling, the response is still governed by the low-frequency conductance, in line with Landauer-Büttiker theory. For smaller couplings, our devices showcase two regimes where the high-frequency response deviates from the low-frequency limit and Landauer-Büttiker theory: When the photon energy exceeds the quantum dot resonance linewidth, degeneracy-dependent plateaus emerge. These are reproduced by sequential tunneling calculations. In the other case with large asymmetry in the tunnel couplings, the high-frequency response is two orders of magnitude larger than the low-frequency conductance G, favoring the high-frequency readout.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
108
issue
20
article number
205417
publisher
American Physical Society
external identifiers
  • scopus:85177986803
ISSN
2469-9950
DOI
10.1103/PhysRevB.108.205417
language
English
LU publication?
yes
id
7f580abe-472b-4278-9718-f71d0dd9b3a8
date added to LUP
2024-01-09 09:15:54
date last changed
2024-01-09 09:17:36
@article{7f580abe-472b-4278-9718-f71d0dd9b3a8,
  abstract     = {{<p>Quantum dots are frequently used as charge-sensitive devices in low-temperature experiments to probe electric charge in mesoscopic conductors where the current running through the quantum dot is modulated by the nearby charge environment. Recent experiments have operated these detectors using reflectometry measurements up to gigahertz frequencies rather than probing the low-frequency current through the dot. In this work, we use an on-chip coplanar waveguide resonator to measure the source-drain transport response of two quantum dots at a frequency of 6 GHz, further increasing the bandwidth limit for charge detection. Similar to that in the low-frequency domain, the response is here predominantly dissipative. For large tunnel coupling, the response is still governed by the low-frequency conductance, in line with Landauer-Büttiker theory. For smaller couplings, our devices showcase two regimes where the high-frequency response deviates from the low-frequency limit and Landauer-Büttiker theory: When the photon energy exceeds the quantum dot resonance linewidth, degeneracy-dependent plateaus emerge. These are reproduced by sequential tunneling calculations. In the other case with large asymmetry in the tunnel couplings, the high-frequency response is two orders of magnitude larger than the low-frequency conductance G, favoring the high-frequency readout.</p>}},
  author       = {{Havir, Harald and Haldar, Subhomoy and Khan, Waqar and Lehmann, Sebastian and Dick, Kimberly A. and Thelander, Claes and Samuelsson, Peter and Maisi, Ville F.}},
  issn         = {{2469-9950}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{20}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B}},
  title        = {{Quantum dot source-drain transport response at microwave frequencies}},
  url          = {{http://dx.doi.org/10.1103/PhysRevB.108.205417}},
  doi          = {{10.1103/PhysRevB.108.205417}},
  volume       = {{108}},
  year         = {{2023}},
}