Achieving the Fundamental Quantum Limit of Linear Waveform Estimation
Abstract
Sensing a classical signal using a linear quantum device is a pervasive application of quantum-enhanced measurement. The fundamental precision limits of linear waveform estimation, however, are not fully understood. In certain cases, there is an unexplained gap between the known waveform-estimation quantum Cramér-Rao bound and the optimal sensitivity from quadrature measurement of the outgoing mode from the device. We resolve this gap by establishing the fundamental precision limit, the waveform-estimation Holevo Cramér-Rao bound, and how to achieve it using a nonstationary measurement. We apply our results to detuned gravitational-wave interferometry to accelerate the search for postmerger remnants from binary neutron-star mergers. If we have an unequal weighting between estimating the signal’s power and phase, then we propose how to further improve the signal-to-noise ratio by a factor of √2 using this nonstationary measurement.
Copyright and License
© 2024 American Physical Society.
Acknowledgement
Code Availability
Data Availability
Files
PhysRevLett.132.130801.pdf
Additional details
Identifiers
- ISSN
- 1079-7114
Funding
- Australian Research Council
- CE170100004
- National Science Foundation
- PHY-2011968
- Simons Foundation
- 568762
- California Institute of Technology
- Institute for Quantum Information and Matter
- Council for Higher Education
- Australian Research Council
- FT210100809
Caltech Custom Metadata
- Caltech groups
- Institute for Quantum Information and Matter , Astronomy Department , TAPIR , LIGO , Physics Department
- Series Name
- LIGO Document
- Series Volume or Issue Number
- P2300096