SciPost Submission Page
Ballistic conductance with and without disorder in a boundary-driven XXZ spin chain
by Adam J. McRoberts, Roderich Moessner
Submission summary
| Authors (as registered SciPost users): | Adam McRoberts |
| Submission information | |
|---|---|
| Preprint Link: | https://arxiv.org/abs/2407.13816v3 (pdf) |
| Date accepted: | 2024-12-04 |
| Date submitted: | 2024-11-28 07:15 |
| Submitted by: | McRoberts, Adam |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Computational |
Abstract
Motivated by recent experiments on Google's sycamore NISQ platform on the spin transport resulting from a non-unitary periodic boundary drive of an XXZ chain, we study a classical variant thereof by a combination of analytical and numerical means. We find the classical model reproduces the quantum results in remarkable detail, and provides an analytical handle on the nature and shape of the spin transport's three distinct regimes: ballistic (easy-plane), subdiffusive (isotropic) and insulating (easy-axis). Further, we show that this phenomenology is remarkably robust to the inclusion of bond disorder -- albeit that the transient dynamics approaching the steady states differs qualitatively between the clean and disordered cases -- providing an accessible instance of ballistic transport in a disordered setting.
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 are writing to resubmit our article, 'Ballistic conductance with and without disorder in a boundary-driven XXZ spin chain', for consideration for publication in SciPost Physics.
We thank you for communicating to us the referee reports, and we thank the referees for their time and assessment of our work.
We are pleased that the referees were broadly positive in their assessment and found the results interesting. We thank them also for their helpful comments and suggestions, which we address in our replies to their reports.
We look forward to your response in due course.
Yours sincerely,
Adam McRoberts and Roderich Moessner
List of changes
--- We have clarified the details of the model near Eq.~(1), splitting the three parts of the timestep across some bullet points to make this easier to read, and explicitly adding the equations of motion.
--- We have expanded the discussion of the quantum-classical correspondence and the role of integrability in \S3.4, pointing out that it is the similarity of the steady states that is responsible for the correspondence, and pointing to the appendix on integrability.
--- We have added an appendix which reports the results of simulations of a model that interpolates between the integrable classical chain and the non-integrable classical Heisenberg chain, showing that the same asymptotic transport regime is observed in all cases (quantum-integrable, classical-non-integrable, and classical-integrable).
--- We have expanded the discussion of the stability of ballistic transport at the start of \S4.2, describing the stability of the steady-states in more detail, and explicitly remarking that the difference $1 - z_{L-1}$ is finite for all configurations of disorder.
Current status:
Editorial decision:
For Journal SciPost Physics: Publish
(status: Editorial decision fixed and (if required) accepted by authors)