Time/frequency high-dimensional entanglement via engineered parametric down conversion

Photonic quantum technologies rely on the deterministic preparation of quantum states encoded in single-photons degrees of freedom. While polarisation, orbital angular momentum and path have been routinely used since the early days of photonic quantum information, the last few years have seen an increasing interest in the frequency-time encoding [1, 2]. Indeed, the possibility of generating high-dimensional states, together with the compatibility of frequency modes and standard optical components, makes the spectral degree of freedom suitable for enhancing the efficiency of quantum protocols, spanning from quantum communication to optical quantum computation.