Practical schemes for the measurement of angular-momentum covariance matrices in quantum optics

Abstract

We develop practical schemes for the measurement of the covariance matrix for intrinsic angular-momentum variables in quantum optics. We particularize this approach to two-beam polarimetry and interferometry, as well as to ensembles of two-level atoms interacting with classical fields. We show the practical advantages of noisy simultaneous measurements.

8 pages, 5 figures. References added and minor changes. Final version

References in corpus (7)

• Beating the Standard Quantum Limit with Four Entangled Photons
• Quantum Non-Demolition Detection of Strongly Correlated Systems
• Covariance matrices and the separability problem
• Entanglement Detection in Optical Lattices of Bosonic Atoms with Collective Measurements
• Characterizing multiparticle entanglement in symmetric N-qubit states via negativity of covariance matrices
• Characterization of quantum angular-momentum fluctuations via principal components
• Local Invariants and Pairwise Entanglement in Symmetric Multi-qubit System