Quantum information processing and communication protocols based on time-bin entangled photonic qudits

Encoding quantum information into time-bin entangled photons offers a physics-rich framework for both fundamental and applied quantum science. Here, we present two frameworks enabling the generation and manipulation of time-bin entangled photonic qudits for both fundamental and applied quantum information processing. The first framework consists of a scalable synthetic temporal photonic lattice implemented on a coupled fiber-loop system that is employed to explore and dynamically control the evolution of the discrete-time quantum walk of time-bin entangled photon states. The other framework consists of a modular, fiber-pigtailed, integrated photonic platform enabling the generation and processing of time-bin entangled qudits that were used to demonstrate the first Bennett-Brassard-Mermin 1992 QKD protocol extended to qudits. We operate the entangled qudits at processing speeds typical of standard telecommunication systems at 10s of GBaud.