Optimized Surface Ion Trap Design for Tight Confinement and Separation of Ion Chains

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The work of the authors Ilya Gerasim, Nikita Zhdanov, Konstantin Kudeyarov, Ksenia Khabarova, Nikolai Kolachevsky and Ilya Semerikov is devoted to the study of traps for ultracold ions. The study of electrode geometries in surface traps undoubtedly has important scientific and technological components for further experimental analysis. The work is written in clear language, the results are suitable for publication in the journal Quantum Reports. However, the authors should discuss in more detail the following issues, which are important for further experimental study of such traps:

It would be necessary to add details about optimizing the shape of the electrode, which cost functions were used to minimize the pseudopotential?

To localize the time-averaged ion position, the authors should discuss in more detail the behavior of static voltage to compensate the ponderomotive force. Have you calculated the ion trajectory in the presence of a magnetic field?

How does the shape of the signal affect the transport characteristics? And how does this affect the transmission of data over low-excitation transitions?

In addition, the entire text should be checked for typos and inaccuracies.

For example, there should be a comma after formula (1)

line  88 «Q, m are …», «h is the distance…»

There should be a dot after formula (2). And it seems that it is not necessary to unnecessarily repeat the expressions in (1) and (2), leaving only the first part in formula (2).

In Figure 3,4, you can delete q = 3 in the color labels of the curves. In Figure 4, the q parameter is specified with an error range, but not in Figure 3?!

Comments on the Quality of English Language

 the entire text should be checked for typos and inaccuracies.

Author Response

Thank you for your comments.

 

Comment 1: It would be necessary to add details about optimizing the shape of the electrode, which cost functions were used to minimize the pseudopotential?

Response 1:  For optimization, we use a calculation grid, from which we chose optimal values. There was no cost function for optimization. We have added a sentence about that. (line 109)

«By exploring various electrode configurations, one can optimize the electrode structure to achieve the desired confining potential. We identified the optimal values for the trapping potential depth, stability parameter, and secular frequencies by calculating them across a grid of possible $w_r$ and $w_c$ values.»

 

Comment 2: To localize the time-averaged ion position, the authors should discuss in more detail the behavior of static voltage to compensate for the ponderomotive force. Have you calculated the ion trajectory in the presence of a magnetic field?

Response 2: In the work, we consider only pseudopotential created by RF electrodes. The consideration of static DC voltages is out of scope. The magnetic field has a negligible impact on ion trapping (https://doi.org/10.1103/RevModPhys.75.281)

 

Comment 3: How does the shape of the signal affect the transport characteristics? And how does this affect the transmission of data over low-excitation transitions?

Response 3:  The shape of the signal affects the speed of separation and ion heating since the field creates the force which move the particle. The consideration of the dynamics of ion chain separation is another important task that we want to study in future research.

 

Comment 4: typos

Response 4: Partially agree. Has been corrected.

We decide to substitute the formula (1) into (2) to emphasize the dependencies of f_rf.

The repeated color labels with q are added to clearly indicate all considered parameters.

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is well written. The research topic is relevant. Quantum computing and quantum cryptography are very popular and necessary now. The article pays little attention to the experimental part and the review of technologies. It is recommended to include the following research articles on the topic in the list of sources:

https://doi.org/10.3390/e23050509

 

 

Author Response

We are grateful for the review.

Response 1: Thank you, but we suppose that the suggested article does not quite fit the topic of our research (we do not discuss quantum cryptography here).

Reviewer 3 Report

Comments and Suggestions for Authors

The authors reports some optimization strategies for surface ion trap design. These strategies and techniques are known to the research and industries in the field. The authors report a particular selected geometry which could be considered an innovation. Overall, I recommend publication of the article. 

 

The authors may like to address this minor comment

 

- line 223 ->The authors hints that the trap is easy to manufacture and it would be appropriate that they mention a method to realize the proposed structure.

Author Response

Thank you for the review.

Comment 1: line 223 ->The authors hints that the trap is easy to manufacture and it would be appropriate that they mention a method to  realize the proposed structure.

Response 1: We agree. We have mentioned the methods that can be used to produce such traps (line 226).

«The design can be produced using  photolithographic techniques and metal deposition on a standard substrate, which allows to achieve the required submicron accuracy. Such a design can be implemented on a single-layer chip.»