  The success of quantum technologies is intimately connected to the
possibility of using them in real-world applications. To this aim, we study the
sensing capabilities of quantum SU(1,1) interferometers in the
single-photon-pair regime and in the presence of losses, a situation highly
relevant to practical realistic measurements of extremely photosensitive
materials. We show that coincidence measurement can be exploited to partially
mitigate the effect of losses inside the interferometer. Finally, we find that
quantum SU(1,1) interferometers are capable of outperforming classical SU(2)
systems when analogous real-world conditions are considered.
