Delocalized correlations in twin light beams with orbital angular momentum

Phys Rev Lett. 2008 Aug 29;101(9):093602. doi: 10.1103/PhysRevLett.101.093602. Epub 2008 Aug 27.

Abstract

We generate intensity-difference-squeezed Laguerre-Gauss twin beams of light carrying orbital angular momentum by using four-wave mixing in a hot atomic vapor. The conservation of orbital angular momentum in the four-wave mixing process is studied as well as the spatial distribution of the quantum correlations obtained with different configurations of orbital angular momentum. Intensity-difference squeezing of up to -6.7 dB is demonstrated with beams carrying orbital angular momentum. Delocalized spatial correlations between the twin beams are observed.