Seminarium Optyczne

Nowadays, with the rapid development of spatially-resolving single-photon detectors, spatially-multimode entangled states start to play a key role in modern quantum science, including quantum communication, computation and imaging schemes. Here we experimentally generate a hybrid bipartite 12-dimensional entangled state of a single photon and collective atomic spin-wave excitation consisting of trillion of atoms. The state lives for an unprecedented time of 6 microseconds, which is two orders of magnitude improvement over hitherto performed experiments. One of the striking properties of the generated micro-macro entangled state is the perfect correlation of positions and anti-correlation of momenta in the photon-atom wavefunction, demonstrated here for the first time. We verify such a state exhibits an original version of the famous Einstein-Podolsky-Rosen paradox [1], namely violation of the Heisenberg inequality with continuous position-momentum variables of two different physical entities. The manipulation of the stored atomic state conditionally on the measurement of the photon provides ways to perform novel tests of the quantum theory or generation of the hyperentanglement. [1] A. Einstein, B. Podolsky, and N. Rosen, Phys. Rev. 47, 777 (1935).