SciPost Submission Page
Spectroscopic Signatures of a Liouvillian Exceptional Spectral Phase in a Collective Spin
by Rafael A. Molina
Submission summary
| Authors (as registered SciPost users): | Rafael Molina |
| Submission information | |
|---|---|
| Preprint Link: | https://arxiv.org/abs/2602.01375v1 (pdf) |
| Code repository: | https://zenodo.org/records/18465840 |
| Date submitted: | Feb. 3, 2026, 9:30 a.m. |
| Submitted by: | Rafael Molina |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
|
| Approach: | Theoretical |
The author(s) disclose that the following generative AI tools have been used in the preparation of this submission:
ChatGPT (version 5.2) was used for technical assistance with figure-formatting code and for proofreading the manuscript. All scientific content and conclusions are the sole responsibility of the author.
Abstract
Non-Hermitian degeneracies of Lindblad generators (Liouvillian exceptional points) can induce non-exponential relaxation and higher-order poles in dynamical response functions. A collective spin coupled to a polarized Markovian bath exhibits an \emph{exceptional spectral phase} in which defective Liouvillian modes imprint super-Lorentzian features in frequency-resolved spectra. We compute the emission spectrum via the Liouvillian resolvent, identify symmetry-sector selection rules, and demonstrate that exceptional-point signatures are strongly state-dependent: they are suppressed in steady-state fluorescence yet become unambiguous for generic (infinite-temperature or random) initial states. Our results provide an experimentally accessible spectroscopic diagnostic of many-body Liouvillian exceptional phases and clarify when steady-state emission can (and cannot) reveal them.
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