OPTICAL-SIMULATION OF QUANTUM LOGIC

A constructive method for simulating small-scale quantum circuits by u se of linear optical devices is presented. It relies on the representa tion of several quantum bits by a single photon, and on the implementa tion of universal quantum gates using simple optical components (beam splitters, phase shifters, etc.). This suggests that the optical reali zation of small quantum networks with present-day quantum optics techn ology is a reasonable goal. This technique could be useful for demonst rating basic concepts of simple quantum algorithms or error-correction schemes. The optical analog of a nontrivial three-bit quantum circuit is presented as an illustration. [S1050-2947(98)50403-9].