Środowiskowe Seminarium z Informacji i Technologii Kwantowych

The advantage of using a single-photon embedded in a two-mode entangled state in two-way communication via maximal violation of an inequality associated with the ‘Guess Your Neighbour’s Input’ (GYNI) game has been theoretically [Phys. Rev. Lett. 120, 060503 (2018)] as well as experimentally [CLEO FID.4 (OSA, 2018)] established recently. We argue that such an advantage can also be obtained using any single-mode pure non-classical state embedded in a two-mode pure entangled state, wherein the other mode is the vacuum (henceforth referred to as a generalized NOON state), regardless of the average photon number of the single mode state. For the special cases of the even-coherent, odd-coherent, and squeezed vacuum NOON states, we establish that the advantage is also maximal. We also show that the usage of the even-coherent NOON states can provide an advantage over the single photon two-mode entangled state under noisy apparatuses (beam splitter and photo detectors). As an aside, we study how some of these generalized NOON states fare in terms of violation of a reference-frame independent Bell-type inequality.