TECHNIQUES FOR PERFORMING LOGIC OPERATIONS USING QUANTUM STATES OF SINGLE PHOTONS

A method and apparatus for performing logic operations using quantum polarization states of single photons, include a first polarizing beam splitter having first input spatial modes and first output spatial modes for a first set of orthogonal polarizations. A second polarizing beam splitter has a second input spatial mode and second output spatial modes for a second set of orthogonal polarizations. The second set of orthogonal polarizations is different from the first set. The second input spatial mode is aligned with a first detected output spatial mode. A single photon detector of multiple single photon detectors is disposed along each one of the second output spatial modes. A first device output carries an output photon based in part on a number of photons detected by the single photon detectors. Such logic operations may be used in quantum computers for quantum information processing.