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Asymmetric power dissipation in electronic transport through a quantum point contact

by Carmen Blaas-Anselmi, Félix Helluin, Rodolfo A. Jalabert, Guillaume Weick, Dietmar Weinmann

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Submission summary

Authors (as registered SciPost users): Guillaume Weick · Dietmar Weinmann
Submission information
Preprint Link:  (pdf)
Date accepted: 2022-02-28
Date submitted: 2022-02-15 10:11
Submitted by: Weinmann, Dietmar
Submitted to: SciPost Physics
Ontological classification
Academic field: Physics
  • Condensed Matter Physics - Theory
Approach: Theoretical


We investigate the power dissipated by an electronic current flowing through a quantum point contact in a two-dimensional electron gas. Based on the Landauer-B\"uttiker approach to quantum transport, we evaluate the power that is dissipated on the two sides of the constriction as a function of the Fermi energy, temperature, and applied voltage. We demonstrate that an asymmetry appears in the dissipation, which is most pronounced when the quantum point contact is tuned to a conductance step where the transmission strongly depends on energy. At low temperatures, the asymmetry is enhanced when the temperature increases. An estimation for the position of the maximum dissipation is provided.

Author comments upon resubmission

Dear editors,
We have revised and further improved our paper in the light of the comments and suggestions made by the referees. We herewith resubmit our work for publication in SciPost Physics.
Sincerely yours,
Carmen Blaas-Anselmi, Félix Helluin, Rodolfo A. Jalabert, Guillaume Weick, Dietmar Weinmann

List of changes

List of changes:

- Following the suggested change 1 of report 1, we have explicitly included a first-order term in the bias voltage in the expansion of the transmission (6), and we discuss its consequences for the expansions (7) and (8) of the dissipated power and the asymmetry below Eq. (8). Moreover, we have moved a sentence about the absence of a first-order correction in bias voltage to the transmission in the case of left-right symmetric systems from a potentially misleading place in the paragraph above Sec. 2.1 to the end of Sec. 2.2.

- Following the suggested change 2 of report 1, we mentioned the electric asymmetry in the discussion at the end of Sec. 2.2.

- Following the suggested change 3 of report 1, as well as the suggested change 2 of report 3, we included a discussion of the difference between the result for an abrupt QPC and a smooth QPC model at the end of the first paragraph of Sec. 3.2.1.

- Following the suggested change 4 of report 1, we alert the reader at the end of the second paragraph of Sec. 3.2.1. about the possible effect of neglected electron-electron interactions at strong bias voltage.

- We have recently been contacted by colleagues working on the atomic-scale structural fluctuations of an STM plasmonic cavity (new Refs. [41,42]), pointing that the very different behavior obtained under the reverse polarization could be explained by the thermal effects that follow from an asymmetric dissipation. We have then included in the conclusions of the revised manuscript a paragraph commenting on a possible link of our results with those of Refs. [41,42].

- We have corrected few mistypes and improved some formulations for better readability.

Published as SciPost Phys. 12, 105 (2022)

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