  By harnessing quantum superposition and entanglement, remarkable progress has
sprouted over the past three decades from different areas of research in
communication computation and simulation. To further improve the processing
ability of microwave pho-tonics, here, we have demonstrated a quantum microwave
photonic processing system using a low jitter superconducting nanowire single
photon detector (SNSPD) and a time-correlated single-photon counting (TCSPC)
module. This method uniquely combines extreme optical sensitivity, down to a
single-photon level (below -100 dBm), and wide processing bandwidth, twice
higher than the transmission bandwidth of the cable. Moreover, benefitted from
the trigger, the system can selectively process the desired RF signal and
attenuates the other in-tense noise and undesired RF components even the power
is 15dB greater than the desired signal power. Using this method we show
microwave phase shifting and frequency filtering for the desired RF signal on
the single-photon level. Besides its applications in space and under-water
communications and testing and qualification of pre-packaged photonic
modulators and detectors. This RF signal processing capability at the
single-photon level can lead to significant development in the high-speed
quantum processing method.
