2010/11/12 by Anand K. Jha, Anand Kumar Jha, Girish S. Agarwal +2 · 90 citations
Computer Science · Mathematics · Physics and Astronomy · #Angular momentum #Angular resolution (graph drawing) #Cold Atom Physics and Bose-Einstein Condensates #Formalism (music) #Interferometry #Mathematics #Optics #Orbital Angular Momentum in Optics #Photon #Photon entanglement #Physics #Quantum #Quantum Information and Cryptography #Quantum entanglement #Quantum mechanics #Total angular momentum quantum number #physics.atom-ph #physics.optics #quant-ph
paper · pdf · doi:10.1103/physreva.83.053829
published in Physical Review A 83(5) (American Physical Society) · 6 pages, 3 figures
arxiv created 2010/11/12 · openalex publication_date 2011/05/20 · arxiv updated 2014/09/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We show that the use of path-entangled states of photons, having nonzero orbital angular momentum (OAM), increases the resolution and sensitivity of angular-displacement measurements performed using an interferometer. In the ideal case of maximally path-entangled states, the resolution of angular-displacement measurements increases by a factor of Nl, while the uncertainty in the measurement of angular displacements scales as 1/Nl, where N is the number of entangled photons, half of which carry, on average, an OAM of +l\ensuremathℏ per photon and the other half carry an OAM of \ensuremath-l\ensuremathℏ per photon. We analyze measurement schemes for two- and four-photon entangled states produced by parametric down-conversion and, by employing a 4\ifmmode×\else\texttimes\fi4 matrix formalism to study the propagation of entangled OAM modes, obtain explicit expressions for the resolution and sensitivity in these schemes. These results constitute an improvement over what could be obtained with N nonentangled photons carrying an orbital angular momentum of |l|\ensuremathℏ per photon.