Demonstration of a Simple Entangling Optical Gate and Its Use in Bell-State Analysis
Nathan K. Langford, Till J. Weinhold, Robert Prevedel, K. J. Resch, Alexei Gilchrist, Jeremy L. O’Brien, Geoff J. Pryde, Andrew G. White · Physical Review Letters · 2005
We demonstrate a new architecture for an optical entangling gate that is significantly simpler than previous realizations, using partially polarizing beam splitters so that only a single optical mode-matching condition is required. We demonstrate operation of a controlled-z gate in both continuous-wave and pulsed regimes of operation, fully characterizing it in each case using quantum process tomography. We also demonstrate a fully resolving, nondeterministic optical Bell-state analyzer based on this controlled-z gate. This new architecture is ideally suited to guided optics implementations of optical gates.