SciPost Submission Page
Hierarchy of degenerate stationary states in a boundary-driven dipole-conserving spin chain
by Apoorv Srivastava, Shovan Dutta
This Submission thread is now published as
Submission summary
| Authors (as registered SciPost users): | Shovan Dutta · Apoorv Srivastava |
| Submission information | |
|---|---|
| Preprint Link: | https://arxiv.org/abs/2411.03309v2 (pdf) |
| Date accepted: | 2025-03-25 |
| Date submitted: | 2025-02-20 05:54 |
| Submitted by: | Dutta, Shovan |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Computational |
Abstract
Kinetically constrained spin chains serve as a prototype for structured ergodicity breaking in isolated quantum systems. We show that such a system exhibits a hierarchy of degenerate steady states when driven by incoherent pump and loss at the boundary. By tuning the relative pump and loss and how local the constraints are, one can stabilize mixed steady states, noiseless subsystems, and various decoherence-free subspaces, all of which preserve large amounts of information. We also find that a dipole-conserving bulk suppresses current in steady state. These exact results based on the flow in Hilbert space hold regardless of the specific Hamiltonian or drive mechanism. Our findings show that a competition of kinetic constraints and local drives can induce different forms of ergodicity breaking in open systems, which should be accessible in quantum simulators.
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
Author comments upon resubmission
We thank the referees for their careful review, useful suggestions, and positive recommendations. We have addressed all of the points raised by the referees in our revised manuscript. We hope it is now suitable for publication in SciPost Physics.
Please find below a list of the changes made. We provide a point-by-point response in our reply to each referee report. We also provide a version of the manuscript with the changes highlighted at: https://shovanduttaorg.wordpress.com/wp-content/uploads/2025/02/2411.03309_diff_v1v2.pdf.
Yours sincerely,
Apoorv Srivastava and Shovan Dutta.
List of changes
*Added a new appendix (Appendix A) to include derivations of state counting.
*Added a sentence in the first paragraph of Sec. 2 to explain local vs global conservation of the dipole moment.
*Expanded the first paragraph of Sec. 3 to include a step-by-step reasoning to arrive at the root configurations.
*Updated Figure 1 to make the pump and loss directions consistent across all the graphs.
*Corrected the second line of Sec. 5 about frozen states.
*Reworded the sentence preceding Eq. (10) on decoherence-free states.
*Updated Eq. (14) and the surrounding text on blockades such that they follow from past discussion.
*Updated published preprints.
*Added new references that are pertinent to the study:
-Ref. [57]: arXiv:2408.10321
-Ref. [69]: Physical Review E 110, 024119 (2024)
-Ref. [70]: Journal of Statistical Mechanics, 023201 (2025)
-Ref. [72]: NIST Handbook of Mathematical Functions, Cambridge University Press, New York (2010).
Published as SciPost Phys. 18, 111 (2025)
Reports on this Submission
Report
I appreciate the comprehensive response provided by the authors addressing all of my queries and concerns. Now the appropriated revisions have been implemented, I recommend this paper for publication. However, there is one small formatting error in which figure 3 appears within the references rather than in Appendix B. This can be trivially corrected so does not need another round of review to address.
Recommendation
Publish (easily meets expectations and criteria for this Journal; among top 50%)
Author: Shovan Dutta on 2025-03-07 [id 5270]
(in reply to Report 1 on 2025-03-06)We thank the referee for the positive recommendation. We are unable to spot the formatting error — in the revised version on arXiv, Figure 3 appears within Appendix B on page 10. We apologize for any oversight on our part.
Anonymous on 2025-03-07 [id 5271]
(in reply to Shovan Dutta on 2025-03-07 [id 5270])Upon checking, the formatting error I found is in the link https://shovanduttaorg.wordpress.com/wp-content/uploads/2025/02/2411.03309_diff_v1v2.pdf rather than the arXiv version so this isn't an issue, apologies for my oversight.