2023/05/01 by Harjot Singh, Jasvith Raj Basani, Singh, Harjot +3
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Mechanical and Optical Resonators #Optics (physics.optics) #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2305.01114
openalex publication_date 2023/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Directing indistinguishable photons from one input port into separate output ports is a fundamental operation in quantum information processing. The simplest scheme for achieving routing beyond random chance uses the photon blockade effect of a two-level emitter. But this approach is limited by a time-energy uncertainty relation. We show that a linear optical unitary transformation applied after the atom enables splitting efficiencies that exceed this time-energy limit. We show that the linear optical unitary improves the splitting efficiency from 67% to 82% for unentangled photon inputs, and from 77% to 90% for entangled photon inputs. We then optimize the temporal mode profile of the entangled photon wavefunction to attain the optimal splitting efficiency of 92%, a significant improvement over previous limits derived using a two-level atom alone. These results provide a path towards optimizing single photon nonlinearities and engineering programmable and robust photon-photon interactions for practical, high-fidelity quantum operations.