Complete control of spatial correlations in quantum-correlated twin beams

Gaurav Nirala,

Center for Quantum Research and Technology (CQRT), Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma;

Siva T. Pradyumna,

Center for Quantum Research and Technology (CQRT), Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma;

Ashok Kumar, 

Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma,

Department of Physics, Indian Institute of Space Science and Technology;

Alberto M. Marino,

Center for Quantum Research and Technology (CQRT), Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma.

Understanding and manipulating the spatial properties of optical quantum states are important for the advancement of real-world applications in quantum imaging and sensing. We report on the complete control of the spatial correlations in quantum-correlated twin beams. We use a four-wave mixing process to generate bright twin beams and show that the distribution of their spatial correlations can be controlled by driving the process with a spatially structured pump. For a Gaussian pump, the spatial cross-correlation between the twin beams is a finite localized region that exhibits spatial quantum correlations. Through a change of the momentum distribution of the pump in a controlled manner, we show that a spatial cross-correlation of any arbitrary complex shape is achievable. Utilizing the infinite-dimensionality of the Hilbert space of the spatial degree of freedom, coupled with the large number of photons ($\sim$ $10^{14}$ photons/s) in each beam, the spatial properties of bright twin beams can be used to encode and transmit information via the multiple spatial optical modes involved in the process.