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Signatures of folded branches in the scanning gate microscopy of ballistic electronic cavities

by Keith R. Fratus, Camille Le Calonnec, Rodolfo A. Jalabert, Guillaume Weick, Dietmar Weinmann

This is not the current version.

Submission summary

As Contributors: Guillaume Weick · Dietmar Weinmann
Arxiv Link: (pdf)
Date submitted: 2021-02-16 13:35
Submitted by: Weinmann, Dietmar
Submitted to: SciPost Physics Core
Academic field: Physics
  • Condensed Matter Physics - Theory
Approach: Theoretical


We demonstrate the emergence of classical features in electronic quantum transport for the scanning gate microscopy response in a cavity defined by a quantum point contact and a micron-sized circular reflector. The branches in electronic flow characteristic of a quantum point contact opening on a two-dimensional electron gas with weak disorder are folded by the reflector, yielding a complex spatial pattern. Considering the deflection of classical trajectories by the scanning gate tip allows to establish simple relationships of the scanning pattern, which are in agreement with recent experimental findings.

Current status:
Has been resubmitted

Author comments upon resubmission

Dear Editors,

We have revised and further improved our manuscript, taking into account all of the comments made by the referees. We herewith resubmit our manuscript for publication in SciPost Physics Core.

With best regards,
Dietmar Weinmann

List of changes


We gave a definition of what is understood by branches, and provided a footnote with a discussion about the difficulties in quantifying them. We included the new reference [7].

Sec. 3.1:
A discussion of the comparison between quantum and classical simulations has been added.

Sec. 3.2:
A footnote on the relation between experimental tip voltage and maximum potential height is added, towards helping to make a quantitative comparison with the experiment.

Sec. 4.:
We have changed the notation of the impact parameter \Delta x -> b, and added a discussion to take into account the precise relation between the impact parameter of radial non-vertical trajectories and the tip position. As a consequence, almost imperceptible changes of the lines in Fig. 4 occur. Accordingly, we have specified the precise parameters used in plotting those lines.
The discussion of effects of the shape of the tip potential has been extended, including the new references [29,30] pointing to experimental and theoretical studies of the tip-induced potential profile.
A discussion of the origin of the effect has been added at the end of the section, with the statement that the precise geometry of the cavity is not essential for the shape of the constant deflection-angle features.

The discussion of the effect of the tip potential shape has been extended.

Appendix A:
A discussion of the presence of arc-like features and their form for different tip potential shapes is added at the end.


Fig. 4: The lines representing Eq. (7) are slightly modified after taking into account the precise dependence of the impact parameter on the tip position. Units have been added to the vertical axis.
Fig. 5: Units have been added to vertical axis.
Figs. 7, 8: Consistently with the change in the text we have relabeled the impact parameter \Delta x -> b.
Fig. 11: We added dashed lines representing the prediction of Eq. (9).

Reports on this Submission

Anonymous Report 3 on 2021-3-5 Invited Report


I confirm that the authors have revised their manuscript according to the questions raised in my first report. Hence I also, a-posteriori, recommend publication, withour further changes.

  • validity: top
  • significance: high
  • originality: good
  • clarity: high
  • formatting: excellent
  • grammar: excellent

Anonymous Report 2 on 2021-2-25 Invited Report


I think that the new version provided by the authors is clearer than the previous one. My main comments/concerns have been taken into account, so I believe that this manuscript is now suited for publication.

  • validity: -
  • significance: -
  • originality: -
  • clarity: -
  • formatting: -
  • grammar: -

Anonymous Report 1 on 2021-2-18 Invited Report


Most of the point I was raising in my first report have been addressed. In some circumstances, and especially for what concerns quantitative comparisons, this is done mainly by pointing to some reference to previous works but without adding new information on the actual problem under study, which is a bit frustrating. However the general point of view taken by the authors, and in particular their main result about the equi-conductance curves have been made significantly clearer. This is a nice paper including useful new information. It can be published in its present form.

  • validity: high
  • significance: good
  • originality: good
  • clarity: good
  • formatting: good
  • grammar: excellent

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