SciPost Submission Page
Coherent Generation and Protection of Anticoherent Spin States
by Jérôme Denis, Colin Read, John Martin
This is not the latest submitted version.
Submission summary
| Authors (as registered SciPost users): | Jérôme Denis · John Martin |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202505_00033v1 (pdf) |
| Code repository: | https://github.com/Jerome-Denis/ACStatesGeneration |
| Data repository: | https://github.com/Jerome-Denis/ACStatesGeneration |
| Date submitted: | May 15, 2025, 2:31 p.m. |
| Submitted by: | John Martin |
| Submitted to: | SciPost Physics Core |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
|
| Approaches: | Theoretical, Computational |
Abstract
We report the first protocol specifically designed to generate anticoherent spin-$j$ states at various orders. The protocol consists of cycles involving a rotation pulse about one axis, followed by a squeezing pulse along a perpendicular direction. To protect these states from decoherence, we develop dynamical decoupling techniques based on group-theoretic sequence design and the dynamically corrected gate formalism. We analyze key sources of dephasing, disorder, and dipole-dipole interactions, and evaluate the effectiveness of our methods in preserving coherence. Potential applications of the generated anticoherent spin states include quantum sensing and studies of quantum entanglement.
Author indications on fulfilling journal expectations
- Address an important (set of) problem(s) in the field using appropriate methods with an above-the-norm degree of originality
- Detail one or more new research results significantly advancing current knowledge and understanding of the field.
Current status:
Has been resubmitted
Reports on this Submission
Strengths
1-This work presents an interesting protocol for generating anti-coherent states at various orders.
2-The manuscript is well organized.
3-The diagrams in this work help understand the protocol and the dynamical decoupling techniques used in this work.
2-The manuscript is well organized.
3-The diagrams in this work help understand the protocol and the dynamical decoupling techniques used in this work.
Weaknesses
1-The common decoherence due to coupling to the environment is not considered.
Report
This manuscript presents a protocol for generating anti-coherent states using pulsed operation of spin squeezing and spin rotation. Anticoherent spin states have a unique property of achieving equal sensitivity to rotations around any direction. Both analytical and numerical results are shown to generate different orders of anticoherent spin states with high fidelity. Dynamical decoupling gates are designed to suppress the noise terms of the system due to local disorder and dipolar interactions.
There are a few technical comments that the authors should address before the manuscript can be accepted.
1-It will be helpful if the expressions of the multipolar tensor operators T_{LM} are provided.
2-Related to 1, it is not clear to me the order of the states in Eqs. (2) and (3).
3-Eq. (5) seems to be unnecessary. Does it help to understand the measure in Eq. (4)?
4-Based on Figure 1, it seems that the population of M=0 and L>=1 states may not be gotten rid of. What is the condition of the rotation operation to pump the population out?
5-How about decoherence due to the environment in N Spin-1/2? Eq. (17) seems to describe imperfection of the system rather than decoherence, which usually needs a master equation to model. The fidelity of the protocol could be much smaller if such a decoherence is included.
6-According to Figure 8, is the dynamical decoupling protocol significant, given the already low infidelity?
There are a few technical comments that the authors should address before the manuscript can be accepted.
1-It will be helpful if the expressions of the multipolar tensor operators T_{LM} are provided.
2-Related to 1, it is not clear to me the order of the states in Eqs. (2) and (3).
3-Eq. (5) seems to be unnecessary. Does it help to understand the measure in Eq. (4)?
4-Based on Figure 1, it seems that the population of M=0 and L>=1 states may not be gotten rid of. What is the condition of the rotation operation to pump the population out?
5-How about decoherence due to the environment in N Spin-1/2? Eq. (17) seems to describe imperfection of the system rather than decoherence, which usually needs a master equation to model. The fidelity of the protocol could be much smaller if such a decoherence is included.
6-According to Figure 8, is the dynamical decoupling protocol significant, given the already low infidelity?
Requested changes
See the comments above.
Recommendation
Ask for minor revision