Heralded single-photon states generated via spontaneous parametric down-conversion with an orbital angular momentum controlled by the pump fieldD.A. Turaykhanov, D.O. Akat’ev, A.V. Shkalikov, V.S. Romanov and A.A. KalachevEPJ Web Conf., 220 (2019) 02018DOI: https://doi.org/10.1051/epjconf/201922002018