SciPost Submission Page
Spin-Orbit Photonics in a Fixed Cavity: Harnessing Bogoliubov Modes of a Bose–Einstein Condensate
by Muqaddar Abbas, Ghaisud Din, and Pei Zhang
This is not the latest submitted version.
Submission summary
| Authors (as registered SciPost users): | Muqaddar Abbas |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202507_00018v1 (pdf) |
| Date submitted: | July 7, 2025, 2:56 a.m. |
| Submitted by: | Muqaddar Abbas |
| Submitted to: | SciPost Physics Core |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Computational |
Abstract
We present a theoretical investigation of spin-orbit photonics within a fixed mirror cavity system containing a Bose-Einstein condensate (BEC), in which the Bogoliubov excitation modes of the condensate are treated as effective mechanical oscillators. By embedding the condensate in a single-mode optical cavity, we explore the emergence and modulation of the photonic spin Hall effect through the spin-dependent transverse shifts of a weak probe field. The optical response—encoded in the real and imaginary components of the output field susceptibility—is systematically analyzed as a function of the condensate–cavity coupling strength, revealing a controllable enhancement or suppression of the spin-orbit interaction. Our model captures how the interplay between collective BEC excitations and cavity photon dynamics induces nontrivial modifications in spin-dependent light propagation. Notably, we uncover that the Bogoliubov mode coupling acts as a tunable channel for mediating spin angular momentum transfer within the cavity, offering a novel route for engineering compact, quantum-coherent spin-orbit photonic devices.
Current status:
Reports on this Submission
Report #2 by Anonymous (Referee 2) on 2025-9-2 (Invited Report)
- Cite as: Anonymous, Report on arXiv:scipost_202507_00018v1, delivered 2025-09-02, doi: 10.21468/SciPost.Report.11844
Strengths
Weaknesses
Report
The problem is of timely interest and the result obtained are – as far as I can judge – correct and new.
Requested changes
The manuscript could be bublished once the authors have expanded section two. The physics of the photonic spin Hall effect is too sketchy and this makes the manuscript difficulto to follow. The desctiption of the effective Bogoliubov modes is somehow clearer – at lest to me as I am familiar with the BEC in cavity dynamics. In general the physicalò setup is rather poorly described.
They should furthermore put in a clearer perspective the novelty of their research and of their approach.
Recommendation
Ask for major revision
Report #1 by Anonymous (Referee 1) on 2025-7-31 (Invited Report)
- Cite as: Anonymous, Report on arXiv:scipost_202507_00018v1, delivered 2025-07-31, doi: 10.21468/SciPost.Report.11675
Strengths
1- Study of photonic spin hall effect and cavity optomechanics 2-Development of theory and visualization of the results
Weaknesses
2-Partially confusing description of the numerical results
Report
Bose–Einstein Condensate'' the photonic spin-Hall effect modified by an optomechanical system. In particular, they investigate the linear response theory of a driven cavity that couples to a mechanical mode of a Bose-Einstein condenstate and use the result for the susceptibility to obtain reflection coefficients and spin-dependent displacements of incident electric field with different polarizations. They visualize their results for various and experimentally realistic parameters and highlight how the spin-selective scattering can be modified by changing model parameters.
In my opinion this is an interesting and timely work and the combination of the photonic spin hall effect with optomechanical cavities in this specific situation is also novel. That said I believe that the needed acceptance criteria for SciPost Physics Core are potentially fulfilled. The main weakness, in my opinion, are several short comings in explaining the derivations and the results. This is why I can only fully recommend this draft for publication after the points below have been clarified.
Requested changes
1) When the authors introduce the pump they do not specify the polarization nor the angle. Regarding Fig. 1, I believe the angle is 0. Could the authors add this information?
2) In Sec. II there are several quantities undefined or defined much later. In general I would recommend that the authors should massively improve Sec. II because at the moment it is hard to follow and almost impossible to reproduce. It would help if the authors spend more time in explaining the equations. For instance: (a) it is unclear where the transfer matrix formalism is used. (b) the permitivity is only defined later in the section (c) all $y_{mn}$ and $p_{mn}$ are not defined as far as I can see. (d) Can the authors give a formula for the total field outside of the cavity incoming and reflected. I think that would make it clearer what $R_s$ and $R_p$ are. (e) It is also not really clear for me that once I have $\chi$, how would I calculate $R_s$ and $R_p$? With the transfer matrix or the formulas (3) and (4)?
3) In Sec. III when the authors introduce the optomechanical system it would be nice to include a few more details. For instance: (a) spotaneous emission is neglected because of far detuning? (b) What about the polarization of the light in the cavity? Where is the magnetic field? Why is it okay to only consider one cavity mode? Why only one internal state of the BEC? (c) There is a damping rate for the mechanical mode introduced? Where does that come from? (d) What about ultra-cold collisions? (e) There is a detuning $\Delta_{\mathbb{P}}$ introduced and I do not understand why? Is it related to $\Delta_p$?
4) I found some small things in Sec. IV that are unclear (maybe there are more) (a) the authors write photonic PSHE but so far they used photonic SHE. Maybe use PSHE everywhere? (b) There is a `` Figure ?? ''. I believe it should be 3? (c) I did not find the definition of $\Delta_p$.
5) Regarding the description of Figure 3 and 4. There are a few things that are unclear to me.
(a) I do not understand the sentence [...] indicating a baseline scenario where spin-dependent reflection is balanced''. Why is it balanced? Also do the authors always choose $\Delta=\omega_m$ here? Is that needed for the symmetry in $\Delta_p$?
(b) I also did not understand[...]becomes increasingly negative, a pronounced asymmetry develops in the angular profile of the ration. [...] sharply increases near resonance , showing enhanced [...]'' What is meant by asymmetry? Just that there is a peak in $\theta$? What means near resonance? I was thinking about a frequency but maybe the authors are refering to $\theta$?
(c) In the description of Fig.4 the authors write [...] a symmetric Lorentzian-like peak is observed [...]''. I do not see any Lorentzian-like peak in Fig. 4. What are the authors refering to?
(d) The authors later write [...]the probe detuning becomes increasingly negative [...] the magnitude of the SHE shift increases, but the peak structure becomes increasingly asymmetric and broadened.[...]'' I am confused by this statement. What peaks should I be looking at? The peaks in $\theta$ become sharper for more negative $\Delta_p$, correct? Also the peaks are very asymmetric from the beginning for all $\Delta_p$. Sorry for my confusion, probably this is just a misunderstanding.
6) Regarding Fig. 5 I have a very minor question. I was wondering why the authors choose $\Delta_p=-0.12\omega_m$? I read in the caption that this corresponds to the maximum photonic SHE. Is that obvious and parameter independent? I mean does this value not depend on $G$?
Recommendation
Ask for minor revision