Distinguishability theory for multiphoton interference with time-resolved photodetection and boson sampling
V. S. Shchesnovich, M. E. O. Bezerra · arXiv (Cornell University) · 2020
We consider possible experimental realization of boson sampling with single photons when fast detectors, capable of precise resolution of photon arrival time, are employed and investigate if such a photodetection allows to circumvent distinguishability of realistic single photons in mixed states. To this goal, we compare the effect of distinguishability of photons in two setups of experimental boson sampling: (a) with photons in the same average (temporal) profile on a spatial interferometer and photodetection incapable of (or with strongly imprecise) time resolution and (b) with photons in generally different average temporal profiles on the same spatial interferometer and photodetection with precise time resolution. Exact analytical results are obtained for Gaussian single photons of different central frequencies with Gaussian distribution of arrival times. We find that distinguishability of photons in the two setups is strikingly similar. For the same purity of photon states, only the same quality experimental boson sampling can be achieved using either of the two considered setups. The upshot of our results is that distinguishability due to mixed states is an intrinsic property of photons, whatever the photodetection scheme.