Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2508.17377 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866912985961725952 |
|---|---|
| author | Liu, Teng Zhang, Xiaohang Zhang, Jiawei Luo, Le |
| author_facet | Liu, Teng Zhang, Xiaohang Zhang, Jiawei Luo, Le |
| contents | The quantum metric, a geometric measure of state-space distance, has recently attracted growing attention for capturing anomalous state responses to parameter variations. Especially in non-Hermitian systems, the quantum metric has been observed to diverge when the eigenstates coalesce, a phenomenon identified as a remarkable resource for sensing. Here, by exploiting this divergence, we establish a non-Hermitian sensing scheme that leverages enhanced transient dynamics to provide a geometric gain for amplifying external field signals. We confirm the critical enhancement in the Fisher information using a trapped-ion 171Yb+ platform and demonstrate superior noise robustness over conventional eigenvalue-splitting--based non-Hermitian schemes by evaluating the minimum detectable signal. Moreover, this scheme can be naturally combined with non-Hermitian topological dynamics, revealing a unique unidirectional sensing response, which indicates its potential for directional signal discrimination. Our work establishes a new paradigm for sensing in open quantum systems through critical quantum geometry and opens a route toward robust topological quantum sensing. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2508_17377 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Non-Hermitian Sensing via a Divergent Quantum Metric Liu, Teng Zhang, Xiaohang Zhang, Jiawei Luo, Le Quantum Physics The quantum metric, a geometric measure of state-space distance, has recently attracted growing attention for capturing anomalous state responses to parameter variations. Especially in non-Hermitian systems, the quantum metric has been observed to diverge when the eigenstates coalesce, a phenomenon identified as a remarkable resource for sensing. Here, by exploiting this divergence, we establish a non-Hermitian sensing scheme that leverages enhanced transient dynamics to provide a geometric gain for amplifying external field signals. We confirm the critical enhancement in the Fisher information using a trapped-ion 171Yb+ platform and demonstrate superior noise robustness over conventional eigenvalue-splitting--based non-Hermitian schemes by evaluating the minimum detectable signal. Moreover, this scheme can be naturally combined with non-Hermitian topological dynamics, revealing a unique unidirectional sensing response, which indicates its potential for directional signal discrimination. Our work establishes a new paradigm for sensing in open quantum systems through critical quantum geometry and opens a route toward robust topological quantum sensing. |
| title | Non-Hermitian Sensing via a Divergent Quantum Metric |
| topic | Quantum Physics |
| url | https://arxiv.org/abs/2508.17377 |