Qudit implementations with broadband energy-time entangled photons

摘要

Entanglement is a key feature of quantum mechanics and is best suited to study the peculiar nature of non-classical correlations. Higher dimensional entangled bipartite systems beyond qubits allow for new insights in generalized Bell inequalities [1] and for enhanced bit rates within protocols for quantum key distribution [2]. Entangled qutrits [3] and ququarts [4] in the time domain have been implemented interferometrically. We propose and demonstrate the capability to encode qudits in the spectrum of energy-time entangled photons by means of spectral amplitude and phase modulation.