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Topological multiferroic order in twisted transition metal dichalcogenide bilayers
by Mikael Haavisto, J. L. Lado, Adolfo Otero Fumega
This Submission thread is now published as
Submission summary
| Authors (as registered SciPost users): | Jose Lado · Adolfo Otero Fumega |
| Submission information | |
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| Preprint Link: | https://arxiv.org/abs/2204.03360v2 (pdf) |
| Date accepted: | 2022-08-16 |
| Date submitted: | 2022-07-12 11:51 |
| Submitted by: | Otero Fumega, Adolfo |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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Abstract
Layered van der Waals materials have risen as powerful platforms to artificially engineer correlated states of matter. Here we show the emergence of a multiferroic order in a twisted dichalcogenide bilayer superlattice at quarter-filling. We show that the competition between Coulomb interactions leads to the simultaneous emergence of ferrimagnetic and ferroelectric orders. We derive the magnetoelectric coupling for this system, which leads to a direct strong coupling between the charge and spin orders. We show that, due to intrinsic spin-orbit coupling effects, the electronic structure shows a non-zero Chern number, thus displaying a topological multiferroic order. We show that this topological state gives rise to interface modes at the different magnetic and ferroelectric domains of the multiferroic. We demonstrate that these topological modes can be tuned with external electric fields as well as triggered by supermoire effects generated by a substrate. Our results put forward twisted van der Waals materials as a potential platform to explore multiferroic symmetry breaking orders and, ultimately, controllable topological excitations in magnetoelectric domains.
Author comments upon resubmission
We are resubmitting our manuscript "Topological multiferroic order in twisted transition metal dichalcogenide bilayers", for consideration in SciPost Physics.
Our manuscript was reviewed by Referee 1, Referee 2 and Referee 3. Referee 1 recommended our manuscript for publication after addressing minor points and highlighting the high quality of the manuscript. Referee 2 stated that the results are interesting and deserve publication, providing useful comments to improve the clarity of the article. Referee 3 reported that our theoretical work is very rich and brings advances in a complex and new subject, it is well presented and deserves to be published in SciPost Physics.
In our revised version, we have addressed all the comments of the Referees and modified our manuscript accordingly.
In this work, we provide a theoretical route to achieve a multiferroic order in a twisted system. Furthermore, we show how to introduce a non-trivial topological character in the system, and how to exploit it along with the multiferroic behavior to achieve a magnetoelectric control of topological excitations. Given all the points above, we hope that you consider our manuscript suitable for publication in SciPost Physics.
Yours sincerely,
Mikael Haavisto, Jose L. Lado and Adolfo O. Fumega
List of changes
- 6 new footnotes (2-7) were added addressing many different points raised by the referees.
- In section 2. Model after eq. (1), the discussion of the model for the twisted system was improved including the response to the comments made by the referees to this point.
- At the beginning of section 3, the first paragraph was added to motivate the choice of the quarter-filling case and to compare it with other fillings. In the third paragraph, a discussion about the interplay between the coulomb parameters to get a multiferroic order was added. The fourth paragraph was added providing estimates of the values of the electric dipole and magnetization that one would obtain in this twisted multiferroic.
- In section 4, the last paragraph was added providing a discussion on the value of the Rashba spin-orbit coupling required to achieve a topological multiferroic.
- In section 5, Fig. 5 was modified accordingly to the referee's comment. In subsection 5.1 at the end of the second paragraph, a discussion on the interface smoothness between different domains and the robustness of the topological states was included. In subsection 5.2, a functional form for the supermoiré potential was included (eq. (7)) with the corresponding explanation. In the final paragraph, a discussion on the interface smoothness between different topological regions was added.
- Overall, we have improved the readability of the article, corrected the typos pointed out by the referees and change the artice style to SciPost style.
Published as SciPost Phys. 13, 052 (2022)
Reports on this Submission
Report
The new manuscript responds well to the remarks and questions I had formulated. As I wrote in my first report, this theoretical work is very rich and brings advances in a complex and new subject the physics of the twisted bilayer semiconductor, and I think it deserves to be published in SciPost Physics.
Report
The authors have answered all the points raised in the Report satisfactorily, which further improved the clarity of the used methods and the derived results presented in the manuscript. Therefore, I recommend publication in SciPost Physics.
Report #1 by Anonymous (Referee 4) on 2022-7-19 (Invited Report)
- Cite as: Anonymous, Report on arXiv:2204.03360v2, delivered 2022-07-19, doi: 10.21468/SciPost.Report.5417
Strengths
1- The manuscript describes an interesting model, currently being intensively studied.
2- The manuscript presents an extensive study of the phase diagram of the model,
3- The manuscript discusses interesting phases, with novel and non trivial properties.
Weaknesses
1- The manuscript discusses generic properties of the model, with little attention to the actual size of the effects which may be, or may be not, observed.
2- The manuscript is vague when discussing the range and relative strength of the parameters of the model.
3- The results are restricted to a narrow range of bands (1) and filling factors (1/4, perhaps also 3/4).
Report
The new version of the manuscript includes a clearer and more in depth discussion of the physical issues addressed in it. I understand that further improvements would imply a substantial change in scope. The manuscript, as it is, is interesting, and it can be published.