Generation of energy-time correlated triphotons in a Kobrak-Rice five-level atomic system
Phys. Rev. A 114, 043727 – Published 19 October, 2026
DOI: https://doi.org/10.1103/48fd-pgn5
Abstract
Narrow-linewidth multiphoton entangled sources with long coherence times are indispensable for quantum information protocols, especially for long-distance quantum communication. Energy-time entangled -class triphotons have recently been observed in hot atomic ensembles, which has advanced the single-step generation of tripartite energy-time entanglement. However, triphotons generated in distinct energy-level systems exhibit highly divergent optical properties, with some systems showing symmetric damped Rabi oscillations and others displaying asymmetric dynamics. Here, we theoretically investigate triphoton generation in a five-level cold atomic system. Linear optical analysis shows that triphoton group velocities approach or exceed the speed of light, indicating that their optical properties are dominated by the fifth-order nonlinear susceptibility. The nonlinear response reveals three spontaneous six-wave mixing pathways. Quantum interference among these processes induces asymmetric Rabi oscillations in threefold coincidence counts, which verifies the temporal sequence of triphoton generation. These findings improve our understanding of triphoton generation and lay a reliable theoretical foundation for related experimental implementations.
