2012/04/30 by Emmanuel Flurin, Nicolas Roch, Francois Mallet +2 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevlett.109.183901
published as Phys. Rev. Lett. 109, 183901 (2012) · 5 pages, 4 figures. Supplementary Information can be found here as an ancillary file
arxiv created 2012/10/31 · arxiv updated 2012/11/02
Using a superconducting circuit, the Josephson mixer, we demonstrate the first experimental realization of spatially separated two-mode squeezed states of microwave light. Driven by a pump tone, a first Josephson mixer generates, out of quantum vacuum, a pair of entangled fields at different frequencies on separate transmission lines. A second mixer, driven by a π-phase shifted copy of the first pump tone, recombines and disentangles the two fields. The resulting output noise level is measured to be lower than for vacuum state at the input of the second mixer, an unambiguous proof of entanglement. Moreover, the output noise level provides a direct, quantitative measure of entanglement, leading here to the demonstration of 6 Mebit.s-1 (Mega entangled bits per second) generated by the first mixer.