SciPost Submission Page
Systematic analysis of relative phase extraction in one-dimensional Bose gases interferometry
by Taufiq Murtadho, Marek Gluza, Khatee Zathul Arifa, Sebastian Erne, Jörg Schmiedmayer, Nelly Huei Ying Ng
Submission summary
| Authors (as registered SciPost users): | Nelly Ng |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202410_00028v1 (pdf) |
| Date submitted: | 2024-10-14 05:56 |
| Submitted by: | Ng, Nelly |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Computational |
Abstract
Interference upon free expansion gives access to the relative phase between two interfering matter waves. In 1D systems, such measurements can be used to reconstruct the spatially-resolved relative phase, which is a key observable in many quantum simulations of quantum field theory and non-equilibrium experiments. However, longitudinal dynamics is typically ignored in the analysis of experimental data. In our work, we give a detailed account of various effects and corrections that occur in finite temperatures due to longitudinal expansion. We provide an analytical formula showing a correction to the readout of the relative phase due to longitudinal expansion and mixing with the common phase. Furthermore, we numerically assess the error propagation to the estimation of the gases' physical quantities such as correlation functions and temperature. We also incorporate systematic errors arising from experimental imaging devices. Our work characterizes the reliability and robustness of interferometric measurements, directing us to the improvement of existing phase extraction methods necessary to observe new physical phenomena in cold-atomic quantum simulators.
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
Thank you for your reply, and for facilitating the review process, especially given the unfortunate delay with the second referee. We appreciate your efforts and are grateful for the positive report we received. We have carefully considered and addressed all the suggestions provided by the current referee. We look forward to the next stage of the review, and hope that the second referee's feedback will be acquired promptly.
We very much appreciate the option to transfer the manuscript to your Core journal, but at this stage we would prefer to proceed with the review process for Scipost Physics. We would however be open to reconsidering the transfer option, if there are further significant delays in securing the second referee.
On behalf of the authors,
Nelly
List of changes
• On page 4, below Eq. (4), we changed ”interference peaks” to ”interference peaks amplitudes” as suggested by the referee.
• In the caption of Fig. 3, we fixed a typo ”amd” to ”and” as pointed out by the referee.
• We changed the histogram style of Fig. 6 and (Fig. 19 in the Appendix) for readability as suggested by the referee. We also fixed a typo 75 (nK) → 75 nK in the caption.
• We revised Sec. 4.4 to incorporate a more comprehensive discussion on the origin of oscillation in the extracted Fourier spectrum.
• In the second paragraph of Sec. 5, we fixed a repetition mistake "noise noise" into "noise".
• Still in the second paragraph of Sec. 5, we changed ”For example, as the atomic cloud scatters light, it receives a momentum transfer which can lead to diffusion of the atoms in the imaging plane and in absorption imaging, the incoming light is in the imaging direction,
which may push the image out of focus.” into ”For example, as the atomic cloud scatters light, it receives a momentum transfer which can lead to diffusion of the atoms in the imaging plane. Moreover, in absorption imaging, the incoming light is in the imaging direction,
which may push the image out of focus.”.
• On page 17, below Fig. 12, we changed ”In our study” to ”In our numerical study”.
• We changed Ref. [45] from ”In-preparation” to the reference to our recent arXiV preprint.
• We modified Eqs. (20)-(22) and the associated discussion in Appendix A to fix a minor algebraic mistake that does not change our main results.
• We added an extra factor of (1-0.5\partial_\eta^2 \phi_+)^{-1} into Eq. (40) in Appendix C.
• As suggested by the referee, we have changed the style of histograms in Fig. 6 and the related figure Fig. 19 in the Appendix. We remove the transparent bars and only draw the edges of the histogram with different colors. We hope that this change can make it easier for the readers to discern the different histograms in both figures.
Current status:
Reports on this Submission
Strengths
1.This paper revisits the study of extraction of the relative phase between two atomic Bose-Einstein condensates under expansion, characterizing the role of longitudinal dynamics during the process.
2.The manuscript is clearly presented, sound and rather extensive.
3.The manuscript is presented in a manner which could be useful to experimental group analysis in the future.
Weaknesses
None
Report
This is an interesting and detailed manuscript investigating the role of longitudinal dynamics during the extraction of the relative phase of two one-dimensional Bose gases. The papers is clearly set in the existing literature, and its aims are very clear. The paper performs a detailed analysis of the impact on different measurable quantities, and also comments on issues related to image processing, making it a very thorough study.
I recommend acceptance of this manuscript.
Requested changes
The only comments I have (after having also seen the other referee report and author response) are the following:
1.How important would the authors expect the role of density fluctuations (ignored in this work) be, and how far do they believe the current findings can be pushed under experimental conditions in the presence of density fluctuations? Perhaps some further discussion on this would be useful.
2.Given that expansion imaging is the standard method of extraction of information, could the authors perhaps comment (more) on the relevance of their findings to:
(i) Ref. [32] (which is duplicated as Ref. [42]): in particular, and noting the existing analysis, would the authors still expect the originally published results to hold reasonably (for all probed observables, most notably the higher ones)? I think the discussion / re-interpretation of that work could have been more extensive/transparent (i.e. whether any key findings are now being cast into question).
(ii) https://doi.org/10.1103/PhysRevLett.130.123401 studied the 1D-3D crossover through expansion imaging and extremely thorough numerics. Can the present analysis also say something about such work? Is there anything that might, for example require re-interpretation?
3. Finally, I was wondering whether the authors were aware of the below manuscript, and -- if not -- whether they thought that some of the presented analysis might be useful in their work:
Piotr Deuar, Comput. Phys. Commun. 208, 92 (2016)
10.1016/j.cpc.2016.08.004 (arXiv:1602.03395 )
A tractable prescription for large-scale free flight expansion of wavefunctions
Recommendation
Publish (easily meets expectations and criteria for this Journal; among top 50%)
Strengths
1. Introduces improvements of currently used method of relative phase measurement.
2. Provides a detailed derivation and strong arguments supporting the new formula for phase estimation.
3. Reveals differences in using the full expansion formula with respect to transversal fit formula in a number of physical quantities.
4. Identifies approximations assumed in the new formula, whose impact will hopefully be addressed in a future work.
Weaknesses
-
Report
This work addresses one of the fundamental measurement in the field of ultracold gases, namely the relative phase extraction from interference patterns between freely expanded matter waves. The authors revised currently used methods used to estimate the phase and proposed an extended, more accurate formula, which includes previously neglected influence of longitudinal expansion on the result of measurement. The 'full expansion formula' (eq. 5) derived in this work is then compared to the 'transversal fit formula' in a reconstruction of different physical quantities.
In general I find the manuscript to be well written and organized. Results of this work are of a high importance, especially for improvement of experimental measurements. Therefore, I recon this work should be published in a high-impact journal.
Recommendation
Publish (easily meets expectations and criteria for this Journal; among top 50%)