SciPost Submission Page
Measurement-induced phase transition in interacting bosons from most likely quantum trajectory
by Anna Delmonte, Zejian Li, Rosario Fazio, Alessandro Romito
Submission summary
| Authors (as registered SciPost users): | Anna Delmonte |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202510_00010v1 (pdf) |
| Date submitted: | Oct. 8, 2025, 2:40 p.m. |
| Submitted by: | Anna Delmonte |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approach: | Theoretical |
The author(s) disclose that the following generative AI tools have been used in the preparation of this submission:
The initial sketches for Figures 1, 3(a) and 3(b) have been improved with AI tools.
Abstract
We propose a new theoretical method to describe the monitored dynamics of bosonic many-body systems based on the concept of the most likely trajectory. We show how such trajectory can be identified from the probability distribution of quantum trajectories, i.e. measurement readouts, and how it successfully captures the monitored dynamics beyond the average state. We prove the method to be exact in the case of Gaussian theories and then extend it to the interacting Sine-Gordon model. Although no longer exact in this framework, the method captures the dynamics through a self-consistent time-dependent harmonic approximation and reveals an entanglement phase transition in the steady state from an area-law to a logarithmic-law scaling.
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
Current status:
Reports on this Submission
Strengths
1) Introduces a deterministic most-likely trajectory approach that is exact for free bosons and conceptually powerful.
2) Extends measurement-induced transition physics to an interacting bosonic field theory (Sine–Gordon), which is largely unexplored.
3) Provides nontrivial physical insight into entanglement scaling under continuous monitoring.
4) Methodologically relevant: avoids stochastic trajectory sampling and may be broadly applicable.
Weaknesses
1) For the interacting case, the most likely trajectory may not reveal the exact behavior and the results further rely on the SCTDHA approximation. This is fine but limitations may be more clearly discussed.
2) Some conceptual aspects (interpretation of most-likely trajectory, comparison to broader MIPT literature) could be clarified to increase accessibility.
Report
The main limitations lie in the interacting-case approximations, whose range of validity is not fully discussed, and in the need for clearer contextualization relative to existing MIPT literature.
Nevertheless, these issues are minor and do not detract from the value of the results. Overall, the manuscript is well suited for publication after minor clarifications that would strengthen its presentation and impact.
Requested changes
It would strengthen the manuscript if the authors provided a more quantitative discussion of the limitations of their approach. In particular, it would be valuable to address how deviations from the most-likely trajectory could manifest, and how such effects might be diagnosed within alternative frameworks, e.g., replica-based treatments or numerical trajectory simulations. Even if a full analysis is beyond scope, clarifying how one would detect or characterize such deviations would considerably improve the reader’s understanding of the method’s range of validity.
Recommendation
Publish (easily meets expectations and criteria for this Journal; among top 50%)