Optica Quantum, 3, 2, 162 – 167 (2025)
We present an experimental platform for linear-optical quantum information processing. Our setup utilizes multiphoton generation using a high-quality single-photon source, which is demultiplexed across multiple spatial channels, a custom-designed, programmable, low-loss photonic chip, and paired with high-efficiency single-photon detectors. We demonstrate the platform’s capability heralded generation of arbitrary two-qubit dual-rail encoded states, including Bell states. Bell states are an invaluable resource for boosting the fusion gates within a photonic quantum computer [Phys. Rev. Lett. 115, 020502 (2015)
Crossref ], The programmable chip was fully characterized through a calibration process that allowed us to create a numerical model that accounts for fabrication imperfections and measurement errors. As a result, using on-chip quantum state tomography (QST), we achieved high-fidelity quantum state preparation, with a fidelity of 98.5% specifically for the Bell state postselected in the dual-rail basis.