Quantum Soliton Collisions: Logic and QND
The Wigner function technique for the quantum theory of nonlinear Schroedinger equation soli-ton collisions is developed. This is applied to experiments on reversible pulse-position switching or logic gates, and to quantum non-demolition (QND) measurements of photon number. A strong limit to cascaded logic gate performance is found, due to rapidly increasing error rates as the number of sequential logic operations is increased. We also obtain bounds on the achievable QND signal-to-noise ratio for quantum soliton collisional measurements of photon number. In this case, a modified strategy of combined phase/amplitude quadrature measurement can give essentially unlimited QND performance, provided thermal noise effects are small.
KeywordsCoherent State Phase Noise Logic Gate Photon Number Reversible Logic
Unable to display preview. Download preview PDF.
- P.D. Drummond, W. Man, (to appear in Opt. Commun).Google Scholar