2021/10/03 by J. O. de Almeida, Maciej Lewenstein, de Almeida, J. O. +3 · 1 citation
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Laser-Matter Interactions and Applications #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.2110.00986
openalex publication_date 2021/10/03 · openalex created_date 2021/10/11 · openalex updated_date 2026/08/02
We demonstrate a method for super-resolving signals encoded as finite mixtures of bosonic modes using collective measurements that exploit permutation symmetry. Specifically, we use multiple copies of the state ρ of the finite mixture to extract an estimate for the purity of ρ via a spectrum measurement, the weak Schur-sampling measurement. Depending on the outcome we then further fine-grain the measurement to optimally extract an estimate of the relative intensity between the two incoherent mixtures. Our protocol furnishes simultaneous estimates for both the relative intensity and the separation of incoherent signals saturating the multi-parameter Cramér-Rao bound, and is robust against misalignment errors. We also provide viable experimental avenues for implementing such collective measurements in different set-ups.