Experimental demonstration of quantum dense coding using entanglement of a two-mode squeezed vacuum state
Jun Mizuno, Kentaro Wakui, Akira Furusawa, Masahide Sasaki · arXiv (Cornell University) · 2004
We have experimentally demonstrated the simultaneous reduction of noises in two canonically conjugate quadratures using the entanglement of a two-mode squeezed state. This scheme was originally proposed for an entanglement-assisted communication with continuous variables [Ban, J. Opt. B 1, L9 (1999), and Braunstein and Kimble, Phys Rev A 61, 042302 (2000)]. In our experiment which realized it in the form originally proposed, a pair of EPR (Einstein-Podolvski-Rosen) beams is generated from two independent squeezed vacua. After adding two-quadrature signal to one of the EPR beams, two squeezed beams which contains the signal were recovered. Such optical addition and subtraction processes are elementary operations of universal quantum information processing on continuous variables.