Bell State Analysis Provides an Optimal Basis Saturating the Quantum Cramer-Rao in Rotation Sensing
Year: 2026
Type: preprint
Abstract: The second-order anti-coherent state of light is known to saturate the Cramer-Rao Bound (QCRB) for rotation sensing around an arbitrary axis. However, due to the complexity of the state and the inefficiency of state tomography, parameter extraction remains an open problem. In this manuscript, we approach the problem of parameter extraction using pairwise Bell state analysis with an additional path degree of freedom. Due to the transformation property of rotation, only the symmetric Bell states will show up in projection in the final state. We exploit this advantage to develop a scheme for extracting the rotation angle for N=4 and N=6 second-order anti-coherent states.
Source: arXiv (Cornell University)
Authors: Bao, Zhuoran, James, Daniel F. V.
Institution: University of Toronto
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7162421362