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Metastability and quantum coherence assisted sensing in interacting parallel quantum dots

Matern, Stephanie LU ; Macieszczak, Katarzyna ; Wozny, Simon LU and Leijnse, Martin LU (2023) In Physical Review B 107(12).
Abstract

We study the transient dynamics subject to quantum coherence effects of two interacting parallel quantum dots weakly coupled to macroscopic leads. The stationary particle current of this quantum system is sensitive to perturbations much smaller than any other energy scale, specifically compared to the system-lead coupling and the temperature. We show that this is due to the presence of a parity-like symmetry in the dynamics, as a consequence of which two distinct stationary states arise. In the presence of small perturbations breaking this symmetry, the system exhibits metastability with two metastable phases that can be approximated by a combination of states corresponding to stationary states in the unperturbed limit. Furthermore, the... (More)

We study the transient dynamics subject to quantum coherence effects of two interacting parallel quantum dots weakly coupled to macroscopic leads. The stationary particle current of this quantum system is sensitive to perturbations much smaller than any other energy scale, specifically compared to the system-lead coupling and the temperature. We show that this is due to the presence of a parity-like symmetry in the dynamics, as a consequence of which two distinct stationary states arise. In the presence of small perturbations breaking this symmetry, the system exhibits metastability with two metastable phases that can be approximated by a combination of states corresponding to stationary states in the unperturbed limit. Furthermore, the long-time dynamics can be described as classical dynamics between those phases, leading to a unique stationary state. In particular, the competition of those two metastable phases explains the sensitive behavior of the stationary current towards small perturbations. We show that this behavior bears the potential of utilizing the parallel dots as a charge sensor, which makes use of quantum coherence effects to achieve a signal to noise ratio that is not limited by the temperature. As a consequence, the parallel dots outperform an analogous single-dot charge sensor for a wide range of temperatures.

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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 B
volume
107
issue
12
article number
125424
publisher
American Physical Society
external identifiers
  • scopus:85151323591
ISSN
2469-9950
DOI
10.1103/PhysRevB.107.125424
project
Theoretical studies on nanoscale thermodynamics and quantum transport
language
English
LU publication?
yes
id
922718f4-f38c-4ad7-b98e-83b45d01d1ea
date added to LUP
2023-05-23 11:02:37
date last changed
2023-11-08 06:11:25
@article{922718f4-f38c-4ad7-b98e-83b45d01d1ea,
  abstract     = {{<p>We study the transient dynamics subject to quantum coherence effects of two interacting parallel quantum dots weakly coupled to macroscopic leads. The stationary particle current of this quantum system is sensitive to perturbations much smaller than any other energy scale, specifically compared to the system-lead coupling and the temperature. We show that this is due to the presence of a parity-like symmetry in the dynamics, as a consequence of which two distinct stationary states arise. In the presence of small perturbations breaking this symmetry, the system exhibits metastability with two metastable phases that can be approximated by a combination of states corresponding to stationary states in the unperturbed limit. Furthermore, the long-time dynamics can be described as classical dynamics between those phases, leading to a unique stationary state. In particular, the competition of those two metastable phases explains the sensitive behavior of the stationary current towards small perturbations. We show that this behavior bears the potential of utilizing the parallel dots as a charge sensor, which makes use of quantum coherence effects to achieve a signal to noise ratio that is not limited by the temperature. As a consequence, the parallel dots outperform an analogous single-dot charge sensor for a wide range of temperatures.</p>}},
  author       = {{Matern, Stephanie and Macieszczak, Katarzyna and Wozny, Simon and Leijnse, Martin}},
  issn         = {{2469-9950}},
  language     = {{eng}},
  number       = {{12}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B}},
  title        = {{Metastability and quantum coherence assisted sensing in interacting parallel quantum dots}},
  url          = {{http://dx.doi.org/10.1103/PhysRevB.107.125424}},
  doi          = {{10.1103/PhysRevB.107.125424}},
  volume       = {{107}},
  year         = {{2023}},
}