Demonstration of Near-Optimal Discrimination of Optical Coherent States

The optimal discrimination of nonorthogonal quantum states with minimum error probability is a fundamental task in quantum measurement theory as well as an important primitive in optical communication. In this work, we propose and experimentally realize a new and simple quantum measurement strategy capable of discriminating two coherent states with smaller error probabilities than can be obtained using the standard measurement devices: the Kennedy receiver and the homodyne receiver.

EU project SECOQC

Lundbeckfonden[R13-A1274]

MEXT[19740253]

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)