Entanglement generation by Fock-state filtration

Resch, K. J.; O'Brien, J. L.; Weinhold, T. J.; Sanaka, K.; White, A. G.

Entanglement generation by Fock-state filtration

Authors

Description

We demonstrate a Fock-state filter which is capable of preferentially blocking single photons over photon pairs. The large conditional nonlinearities are based on higher-order quantum interference, using linear optics, an ancilla photon, and measurement. We demonstrate that the filter acts coherently by using it to convert unentangled photon pairs to a path-entangled state. We quantify the degree of entanglement by transforming the path information to polarisation information, applying quantum state tomography we measure a tangle of T=(20+/-9)%.
4 pages, 3 figures