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Current-induced re-entrant superconductivity and extreme nonreciprocal superconducting diode effect in valley-polarized systems
by Yu-Chen Zhuang and Qing-Feng Sun
Submission summary
| Authors (as registered SciPost users): | Yu-Chen Zhuang |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202505_00037v2 (pdf) |
| Date accepted: | Dec. 17, 2025 |
| Date submitted: | Nov. 15, 2025, 12:57 p.m. |
| Submitted by: | Yu-Chen Zhuang |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approach: | Theoretical |
Abstract
The superconducting diode effect (SDE) refers to the nonreciprocity of superconducting critical currents. Generally, the SDE has a positive and a negative critical currents jc± corresponding to two opposite directions with unequal amplitudes. It is demonstrated that an extreme nonreciprocity where two critical currents can become both positive (or negative) has been observed in twisted graphene systems. In this work, we theoretically propose a possible mechanism to realize an extreme nonreciprocal SDE. Based on a simple microscopic model, we demonstrate that depairing currents required to dissolve Cooper pairs can be remodulated under the interplay between valley polarizations and applied currents. Near the disappearance of the superconductivity, the remodulation is shown to induce extreme nonreciprocity and also the current-induced re-entrant superconductivity where the system has two different critical current intervals. Our study may provide new horizons for understanding the coexistence of superconductivity and spontaneous valley polarizations, and pave a way for designing SDE with 100% efficiency.
Author indications on fulfilling journal expectations
- Provide a novel and synergetic link between different research areas.
- Open a new pathway in an existing or a new research direction, with clear potential for multi-pronged follow-up work
- Detail a groundbreaking theoretical/experimental/computational discovery
- Present a breakthrough on a previously-identified and long-standing research stumbling block
Author comments upon resubmission
List of changes
1) We revised the Fig. 1 and Fig. 3 to make our theory more clear. 2) We add some explanations in 2nd, 3rd and 4th paragraphs of Page 7 to illustrate the logic of our theory to determine actual critical currents. 3) We add a new appendix (Appendix. C) with a new figure (Fig. 7) to discuss the effect of trigonal warping. 4) We add a new appendix (Appendix. D) with a new figure (Fig. 8) to discuss the coupling between supercurrents and valley polarizations. 5) We add some discussions about the estimation of α± in a more realistic tight-binding model in Appendix. E with a new figure (Fig. 9). 6) We add some statements in the section of ‘Discussions and conclusion’ to emphasis some correspondences between our theoretical calculations and experimental observations. 7) Some new references are cited, see Refs. 4, 28, 29, 40, 80-85.
Current status:
Editorial decision:
For Journal SciPost Physics: Publish
(status: Editorial decision fixed and (if required) accepted by authors)
Reports on this Submission
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Appendix D contains an equilibrium model describing superconductivity and valley polarization on equal footing, and discusses the general structure of the supercurrent-VP coupling qualitatively. If quantitative calculations were done based on this, one could also give clearer statements of details such as stability of the different solution branches.
Although the discussion could be expanded in various directions, the revisions appear sufficient to answer questions raised in the previous review, and the text is probably suitable for publication.
Recommendation
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In my opinion, this paper presents an extensive and sound study. The paper is written clearly, and the results are presented in a reasonable manner. The topic itself is interesting and should be of interest both to theoreticians and to experimentalists working in the field.
The paper has already gone through one round of reviews. The main point raised in the reviews concerned trigonal warping and the applicability of the adopted model for current-induced valley polarization. I find the authors response satisfactory, and since the paper provides clear predictions, future experiments will further verify the validity of the presented study.
In my opinion, this work is an important contribution to the field, and I recommend its publication.
Recommendation
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Report #1 by Jin-Xin Hu (Referee 1) on 2025-11-15 (Invited Report)
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Recommendation
Publish (easily meets expectations and criteria for this Journal; among top 50%)