A High-Reliability Quantum Communication Protocol via Controllable-Signal Attenuation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The author proposed to describe the details of the optimized protocol based on counterfactual communication. The inevitable degradation limits the number of beam splitters was explored. Moreover, they provided the experimental evidence for a high-reliability quantum communication protocol using this method. The work is logical and well-reasoned, and the results are interesting. However, I do not recommend it for publication in the present form.

1.     In Abstract, the authors should emphasized how to a high-reliability communication protocol by controllable-signal attenuation. Results? Advantages, etc.? Also the abstract should be refined.

2.     In Fig. 2, why the reliability increase with the decrease of N for degradation is larger than 0.003?

3.     The authors discussed the direct communication protocol with degradation. While some investigations about quantum secure direct communication are missed, such as [One-step quantum secure direct communication. Science Bulletin 67(4):367-374 (2022); One-step device-independent quantum secure direct communication. Science China Physics, Mechanics & Astronomy 65, 250311 (2022); Device-Independent Quantum Secure Direct Communication with Single-Photon, Phys. Rev. Appl. 19, 014036 (2023); Measurement-device-independent three-party quantum secure direct communication, Quantum. Inf. Process. 22, 111 (2023)].

4.     Why the 100% high-reliability of quantum communication can be realized when unavoidable degradation exists? Is this protocol robust against the type of noise?

5.     How about reliability with respect to the degradation for logic 0?

Comments on the Quality of English Language

Minor correction.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The authors present a protocol for high-reliability quantum communication using controllable-signal attenuation. The paper tackles the practical limitations of counterfactual quantum communication protocols, focusing on the challenges posed by degradation and the finite number of beam splitters. Through numerical simulations and experimental validations, the study demonstrates that high-reliability communication is achievable even with imperfect interferometers by employing signal attenuation correction methods.

 

The paper introduces a method of using controllable-signal attenuation to mitigate the effects of degradation in quantum communication systems. This is a significant advancement in the field of quantum communication. The authors provide a detailed theoretical framework supported by numerical simulations. The experimental setup and results further validate the theoretical predictions, enhancing the credibility of the findings.

 

1. To appeal to a wider audience in the QKD community, the introduction should include recent developments/overviews from these fields such as:

   - "The quantum internet: A synergy of quantum information technologies and 6G networks." IET Quantum Communication 4.4 (2023): 147-166.

   -“Path-encoded high-dimensional quantum communication over a 2-km multicore fiber." npj Quantum Information 7.1 (2021): 63.  

   - "All-optical long-distance quantum communication with Gottesman-Kitaev-Preskill qubits." Physical Review Research 3.3 (2021): 033118.

2. In all figures, a complete description of the setup should be provided including the definitions of BS, HR, PZT and the detectors.

3. Is there a citation for Eq. 1?

4. The data in Figure. 3 looks like a simulation. Is it simulated? Can you clarify in the paper what is simulated and what is experimental in the paper? Is Figure 6 the only experimental plot?

5. In Figure 6, please write a full caption describing the data and the fitted plot reference.

6. In the conclusions, can you clearly state the most important findings of your study? Highlight how the method of controllable-signal attenuation improves reliability in practical quantum communication systems.

You can also discuss the wider implications of your results. Explain how your findings can be applied to real-world quantum communication and what this means for the field.

Finally, you can mention any limitations of your study. This includes any assumptions in your theoretical models and potential areas where further research is needed to address these limitations.

 

 

Provided these suggestions are carried out, the paper might be be suitable for publication.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Please see the attachment. 

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

In the manuscript entitled “A high-reliability quantum communication protocol via controllable-signal attenuation”, it is an extension of a protocol proposal (SLAZ, initial letters of the names of the four authors) for counterfactual quantum communication presented in Ref.[14]. The authors of this manuscript propose a method for correcting losses arising from the use of several Beam-Splitters, which seeks to improve the reliability and efficiency of communication. They also seek to provide experimental evidence for this high-reliability quantum communication protocol. The text has its specific value, but is quite incomplete. A very large number of acronyms are used, such as HR, HRM, BSM, BSMS, without their proper specifications, starting with those in Fig. (1) and in many parts of the text. The captions for the figures are very poor and say little or nothing about the content of the figures. The Ref.[14] would help to clarify and greatly improve the text of this manuscript. Various quantities are used without their definitions, such as probabilities P1, P2, etc. It has several incongruous sentences, such as the sentence in lines 167 to 170, which is not consistent with Fig. (2a).

In Fig. (4b) there is an insert that has nothing to do with the text. The 1 present there must be the 1 of the text as mentioned in the caption of the figure itself.

Finally, I am of the opinion that the authors should give a more in-depth explanation of the great similarity between the mentioned Zeno effect and the increase in beam splitters in the protocol, since beam splitters, among other factors, are elements of strong degradation of quantum states involved in communication.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors addressed all the points I made, and I recommand it to publish in Photonics.

Reviewer 3 Report

Comments and Suggestions for Authors

All my initial inquiries were answered satisfactorily.