Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 15, 2019 | Published + Submitted
Journal Article Open

Fundamental relations between measurement, radiation, and decoherence in gravitational wave laser interferometer detectors

Abstract

As laser interferometer gravitational wave (GW) detectors become quantum noise dominated, understanding the fundamental limit on measurement sensitivity imposed by quantum uncertainty is crucial to guide the search for further noise reduction. Recent efforts have included applying ideas from quantum information theory to GW detection—specifically the quantum Cramer-Rao bound, which is a minimum bound on error in parameter estimation using a quantum state and is determined by the state's quantum Fisher information (QFI) with respect to the parameter [Helstrom, J. Stat. Phys. 1, 231 (1969)]. Identifying the QFI requires knowing the interaction between the quantum probe and the signal, which was rigorously derived for GW interferometer detectors in Pang and Chen [Phys. Rev. D 98, 124006 (2018)]. In this paper, we calculate the QFI and fundamental quantum limit (FQL) for GW detection, and furthermore we derive explicit reciprocity relations involving the QFI that summarize information exchange between the detector and a surrounding weak quantum GW field. Specifically, we show that the GW power radiation by the detector's quantum fluctuations are proportional to the QFI, and therefore are inversely proportional to its FQL. Similarly, the detector's decoherence rate in a white noise GW bath can be explicitly related to the QFI/FQL. These relations are fundamental and appear generalizable to a broader class of quantum measurement systems.

Additional Information

© 2019 American Physical Society. Received 22 March 2019; published 11 June 2019. We thank Bassam Helou, Yiqiu Ma, Haixing Miao, Rana Adhikari, and Yuri Levin for discussions. Our research is supported by the Simons Foundation (Grant No. 568762) and the National Science Foundation, through Grants No. PHY-1708212 and No. PHY-1708213.

Attached Files

Published - PhysRevD.99.124016.pdf

Submitted - 1903.09378.pdf

Files

PhysRevD.99.124016.pdf
Files (693.5 kB)
Name Size Download all
md5:0ec20f0ec3f9cf0282a52a5686d8b4e8
415.1 kB Preview Download
md5:b5e48f166bf59a1726d9ff8d167c9658
278.5 kB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023