Engineering of optical continuous-variable qubits via displaced photon subtraction: multimode analysis
Masahiro Takeoka, Jonas Schou Neergaard-Nielsen, Makoto Takeuchi, Kentaro Wakui, Hiroki Takahashi, K. Hayasaka, Masahide Sasaki · Journal of Modern Optics · 2010
We investigate the practical scheme of engineering a qubit of two optical continuous-variable states, based on squeezed vacuum and coherently displaced photon subtraction. A fully multimode model is developed to describe a continuous wave (cw) setting of the experiment, which has been successfully implemented to generate highly pure non-classical states. The model agrees well with the experimental results and the numerical results show that the intrinsic imperfection due to the cw nature of the source is relatively small. Our photon subtraction technique could also be useful for preparing optical Schrödinger's cat-like states in arbitrary superposition, which is a basic qubit resource for linear optics coherent state quantum computing.