Violating Bell inequalities with entangled optical frequency combs and multipixel homodyne detection

摘要

We have theoretically investigated the possibility of using any of several continuous-variable Bell-type inequalities-for which the dichotomic measurements are achieved with coarse-grained quadrature (homodyne) measurements-in a multiparty configuration where each participant is given a section, in the frequency domain, of the output of an optical parametric oscillator which has been synchronously pumped with a frequency comb. Such light sources are undergoing intense study due to their novel properties, including the potential for production of light entangled in many hundreds of physical modes-a critical component for many proposals in optical or hybrid-optical quantum computation proposals. The situation we study notably uses only highly efficient optical homodyne detection, meaning that in such systems the fair-sampling loophole would be relatively easy to avoid.