Optical quantum computing
In 2001, all-optical quantum computing became feasible with the discovery that scalable quantum computing is possible using only single-photon sources, linear optical elements, and single-photon detectors.
Author: Jeremy O'Brien, Science Vol. 318, Issue 5856 - Published: Dec 07, 2007
Demonstration of an all-optical quantum controlled-NOT gate
The promise of tremendous computational power, coupled with the development of robust error-correcting schemes, has fuelled extensive efforts to build a quantum computer.
Author: J. L. O'Brien, G. J. Pryde, A. G. White, T. C. Ralph & D. Branning, Nature volume 426, pages 264–267 - Published: Nov 20, 2003