SciPost Submission Page
Muonium reaction in MgO: A showcase for the final steps of ion implantation
by Rui C. Vilão, Ali Roonkiani, Apostolos G. Marinopoulos, Helena V. Alberto, João M. Gil, Ricardo B. L. Vieira, Robert Scheuermann and Alois Weidinger
Submission summary
| Authors (as registered SciPost users): | Apostolos Marinopoulos · Rui Vilão |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202504_00035v3 (pdf) |
| Date accepted: | Aug. 4, 2025 |
| Date submitted: | July 23, 2025, 11:57 a.m. |
| Submitted by: | Rui Vilão |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
|
| Approaches: | Theoretical, Experimental |
Abstract
We present an in-depth investigation of the implantation of positive muons in magnesium oxide (MgO). Muonium, the positive muon plus an electron is an analogue of the hydrogen atom. This study describes the final stage of the implantation process, from muon diffusion over the potential barrier and the stopping by an inelastic reaction to the final embedding of the muon into the lattice structure. A special aspect is a relatively long-lived intermediate configuration which lasts for several hundred nanoseconds or more and is accessible to muon spin spectroscopy. The model presented here provides a framework for the analysis of the general case of ion implantation.
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
Published as SciPost Phys. Core 8, 056 (2025)
Reports on this Submission
Report #2 by Jess Brewer (Referee 3) on 2025-7-30 (Invited Report)
- Cite as: Jess Brewer, Report on arXiv:scipost_202504_00035v3, delivered 2025-07-30, doi: 10.21468/SciPost.Report.11671
Strengths
- Substantial and thorough measurements of muSR spectra in the sample.
- Sophisticated use of DFT calculations to determine muon & muonium sites and lattice responses.
- Ingenious deployment of a toy model.
Weaknesses
- Electric field measurements that conflict with the model are ignored completely.
- Unshakeable faith in a toy model.
Report
Requested changes
None at this point.
Recommendation
Publish (easily meets expectations and criteria for this Journal; among top 50%)
Report #1 by Anonymous (Referee 4) on 2025-7-24 (Invited Report)
- Cite as: Anonymous, Report on arXiv:scipost_202504_00035v3, delivered 2025-07-24, doi: 10.21468/SciPost.Report.11628
Report
The model itself does not stand critics expressed in Phys. Rev. B 101, 077201 (2020), in particular, regarding timescales and energies involved.
Recommendation
Reject
Anonymous on 2025-07-30 [id 5694]
The "anonymous" Referee is obviously one of my coauthors on the critique paper Phys. Rev. B 101, 077201 (2020) who is less charitable than I am regarding the intransigence of Vilao et al. My position is that the authors of the current paper should be given all the rope they need to hang themselves in public, but I have a lot of sympathy for my own coauthors: Vilao et al. have again systematically ignored the results of our electric field experiments, presumably because those results are incompatible with their "transition state" (a.k.a. "doorway state") model. I mention all this because I am sorely tempted to just agree with the other Referee and reject this paper, but I feel more obliged to acknowledge the ingenuity of their model and the detailed experiments they have done this time, and leave the ultimate evaluation to general scientific consensus, which requires publication. Ultimately, the hard decision is in the Editor's hands.