Quantum Metrology: Dynamics vs. Entanglement

Abstract

A parameter whose coupling to a quantum probe of $n$ constituents includes all two-body interactions between the constituents can be measured with an uncertainty that scales as $1/n^{3/2}$, even when the constituents are initially unentangled. We devise a protocol that achieves the $1/n^{3/2}$ scaling without generating any entanglement among the constituents, and we suggest that the protocol might be implemented in a two-component Bose-Einstein condensate.

4 pages, 1 figure

References in corpus (4)

• Generalized Limits for Single-Parameter Quantum Estimation
• Quantum-limited metrology with product states
• A nonlinear Ramsey interferometer operating beyond the Heisenberg limit
• Quantum limited measurements of atomic scattering properties

Cited by in corpus (4)

• Spin squeezing in a generalized one-axis twisting model
• Nonlinear quantum metrology using coupled nanomechanical resonators
• Quantum fluctuations in the image of a Bose gas
• Dispersion and fidelity in quantum interferometry