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Bilateral photon emission from a vibrating mirror and multiphoton entanglement generation
by Alberto Mercurio, Enrico Russo, Fabio Mauceri, Salvatore Savasta, Franco Nori, Vincenzo Macrì, Rosario Lo Franco
Submission summary
| Authors (as registered SciPost users): | Alberto Mercurio |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202406_00013v1 (pdf) |
| Date submitted: | 2024-06-06 00:09 |
| Submitted by: | Mercurio, Alberto |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approach: | Theoretical |
Abstract
Entanglement plays a crucial role in the development of quantum-enabled devices. One significant objective is the deterministic creation and distribution of entangled states, achieved, for example, through a mechanical oscillator interacting with confined electromagnetic fields. In this study, we explore a cavity resonator containing a two-sided perfect mirror. Although the mirror separates the cavity modes into two independent confined electromagnetic fields, the radiation pressure interaction gives rise to high-order effective interactions across all subsystems. Depending on the chosen resonant conditions, which are also related to the position of the mirror, we study $2n$-photon entanglement generation and bilateral photon pair emission. Demonstrating the non-classical nature of the mechanical oscillator, we provide a pathway to control these phenomena, opening potential applications in quantum technologies. Looking ahead, similar integrated devices could be used to entangle subsystems across vastly different energy scales, such as microwave and optical photons.
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
Current status:
Reports on this Submission
Strengths
1- The paper is presented very clearly.
2- The physics presented is rich and intriguing
3- The numerical corroboration of the analytical results is solid and convincing.
Weaknesses
1- The phenomenon presented cannot be implemented easily in an experiment
Report
The authors present an extension of a previous work (Ref 38), where they make use of the dynamical Casimir effect to effectively couple the radiation modes between two modes that are coupled by a moving mirror with perfect reflectivity.
The derivation of the Hamiltonian in Ref 38 is solid, and so did their first presentation of two photon hopping. In this work, the authors explore further resonance conditions and show how 2n photon entanglement occurs, and how the Janus emission (terminology introduced ad hoc) arises.
I enjoyed very much reading their work, I found the language fluent and precise, the mathematical derivations rigorous, the intuition clear, and the numerical corroborations convincing. Overall, I do not have any technical request or questions, except the following small point: why do you define the effective annihilation operator of the dressed mode as $\chi^+$? This seems counter-intuitive, but maybe it is related to some other consideration that gives the meaning to the + and - parts...
Also, I would like to point out that--to my knowledge--there is no experimental implementation of the dynamical Casimir effect to date. To do so, one would need to observe a mechanical displacement close to the speed of light, and the community is not there yet. Instead, the observed dynamical Casimir effects to date are in circuits whose electronic properties mimic those of the mechanical problem. It is also in this kind of settings that we can hope to observe the theoretical predictions of the current manuscript in the short-term future.
Requested changes
-- I would like to ask for a small inset in Fig. 3(a) where it is shown a bit more clearly how the lines oscillate in the intermediate part. Right now, it is not straightforward to see this without the help from the description in the text.
-- I would also like to ask the authors to make more clear in the introduction that the experiments that are more likely to reproduce the physics presented are electronic analogues rather that an optomechanical system.
Recommendation
Publish (easily meets expectations and criteria for this Journal; among top 50%)
Author: Alberto Mercurio on 2024-10-28 [id 4905]
(in reply to Report 1 on 2024-10-02)We thank the Referee for the detailed report of our manuscript, and for considering the physics presented in this work as "rich and intriguing". In the following, we provide responses to the raised comments.
Referee's Comment 1
Authors Reply
We thank the Referee for having raised this important question.
The description of an open quantum system in terms of dressed operators is more general than using the "bare" operators in the Lindblad form. This approach is thoroughly discussed in the book The Theory of Open Quantum Systems by Breuer and Petruccione, and then applied to ultrastrongly coupled systems in, e.g., Refs [30,57] of the current Manuscript. In the limit of linear systems and weak coupling, the standard Lindblad form is restored. Here, we used the dressed operators to have a more general description of our system, but we could also use the standard Lindblad form, with similar results. The physical meaning of $\hat{\mathcal{X}}^+$ is to get an operator that only oscillates with positive frequencies. It is the analogous of the annihilation operator $\hat{a}$, which oscillates as $e^{-i \omega t}$ for a linear system. More generally, the $\hat{\mathcal{X}}^+$ operator would involve multiple positive frequencies.
Referee's Comment 2
Authors Reply
We completely agree with the Refeeree. We acknowledge that observing this effect in optomechanical platforms remains challenging. However, as the Referee points out, it may be observable in circuit QED simulators.
Hence, we have revised the manuscript to include a more detailed explanation of this point.
Referee's Comment 3
Authors Reply
We modified the layout of Fig. 3(a) to include an inset that highlights the intermediate oscillations more clearly.
Referee's Comment 4
Authors Reply
As noted in our response to Referee’s Comment 2, we have revised the introduction to clarify that electronic analogues are more likely than optomechanical systems to reproduce the physics presented. The manuscript has been updated accordingly.