Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Power, efficiency and fluctuations in a quantum point contact as steady-state thermoelectric heat engine

Kheradsoud, Sara LU ; Dashti, Nastaran LU ; Misiorny, Maciej ; Potts, Patrick P. LU orcid ; Splettstoesser, Janine and Samuelsson, Peter LU (2019) In Entropy 21(8).
Abstract

The trade-off between large power output, high efficiency and small fluctuations in the operation of heat engines has recently received interest in the context of thermodynamic uncertainty relations (TURs). Here we provide a concrete illustration of this trade-off by theoretically investigating the operation of a quantum point contact (QPC) with an energy-dependent transmission function as a steady-state thermoelectric heat engine. As a starting point, we review and extend previous analysis of the power production and efficiency. Thereafter the power fluctuations and the bound jointly imposed on the power, efficiency, and fluctuations by the TURs are analyzed as additional performance quantifiers. We allow for arbitrary smoothness of... (More)

The trade-off between large power output, high efficiency and small fluctuations in the operation of heat engines has recently received interest in the context of thermodynamic uncertainty relations (TURs). Here we provide a concrete illustration of this trade-off by theoretically investigating the operation of a quantum point contact (QPC) with an energy-dependent transmission function as a steady-state thermoelectric heat engine. As a starting point, we review and extend previous analysis of the power production and efficiency. Thereafter the power fluctuations and the bound jointly imposed on the power, efficiency, and fluctuations by the TURs are analyzed as additional performance quantifiers. We allow for arbitrary smoothness of the transmission probability of the QPC, which exhibits a close to step-like dependence in energy, and consider both the linear and the non-linear regime of operation. It is found that for a broad range of parameters, the power production reaches nearly its theoretical maximum value, with efficiencies more than half of the Carnot efficiency and at the same time with rather small fluctuations. Moreover, we show that by demanding a non-zero power production, in the linear regime a stronger TUR can be formulated in terms of the thermoelectric figure of merit. Interestingly, this bound holds also in a wide parameter regime beyond linear response for our QPC device.

(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
keywords
Fluctuations, Heat engines, Mesoscopic physics, Quantum transport, Thermodynamic uncertainty relations, Thermoelectricity
in
Entropy
volume
21
issue
8
article number
777
publisher
MDPI AG
external identifiers
  • scopus:85070463283
ISSN
1099-4300
DOI
10.3390/e21080777
language
English
LU publication?
yes
id
eae48260-a5a8-4815-a61b-1df554a70293
date added to LUP
2019-08-26 14:54:51
date last changed
2023-11-19 13:18:05
@article{eae48260-a5a8-4815-a61b-1df554a70293,
  abstract     = {{<p>The trade-off between large power output, high efficiency and small fluctuations in the operation of heat engines has recently received interest in the context of thermodynamic uncertainty relations (TURs). Here we provide a concrete illustration of this trade-off by theoretically investigating the operation of a quantum point contact (QPC) with an energy-dependent transmission function as a steady-state thermoelectric heat engine. As a starting point, we review and extend previous analysis of the power production and efficiency. Thereafter the power fluctuations and the bound jointly imposed on the power, efficiency, and fluctuations by the TURs are analyzed as additional performance quantifiers. We allow for arbitrary smoothness of the transmission probability of the QPC, which exhibits a close to step-like dependence in energy, and consider both the linear and the non-linear regime of operation. It is found that for a broad range of parameters, the power production reaches nearly its theoretical maximum value, with efficiencies more than half of the Carnot efficiency and at the same time with rather small fluctuations. Moreover, we show that by demanding a non-zero power production, in the linear regime a stronger TUR can be formulated in terms of the thermoelectric figure of merit. Interestingly, this bound holds also in a wide parameter regime beyond linear response for our QPC device.</p>}},
  author       = {{Kheradsoud, Sara and Dashti, Nastaran and Misiorny, Maciej and Potts, Patrick P. and Splettstoesser, Janine and Samuelsson, Peter}},
  issn         = {{1099-4300}},
  keywords     = {{Fluctuations; Heat engines; Mesoscopic physics; Quantum transport; Thermodynamic uncertainty relations; Thermoelectricity}},
  language     = {{eng}},
  month        = {{08}},
  number       = {{8}},
  publisher    = {{MDPI AG}},
  series       = {{Entropy}},
  title        = {{Power, efficiency and fluctuations in a quantum point contact as steady-state thermoelectric heat engine}},
  url          = {{http://dx.doi.org/10.3390/e21080777}},
  doi          = {{10.3390/e21080777}},
  volume       = {{21}},
  year         = {{2019}},
}