Two-detector reconstruction of multiphoton states in linear optical networks
Tudor-Alexandru Isdrailă, Jun-Yi Wu · Physical Review Research · 2025
We propose a method for partial state reconstruction of multiphoton states in multimode ( N -photon M -mode) linear optical networks (LONs) employing only two bucket photon-number-resolving detectors. The reconstructed Heisenberg-Weyl-reduced density matrix captures quantum coherence and symmetry with respect to Heisenberg-Weyl operators. Employing deterministic quantum computing with one qubit (DQC1) circuits, we reduce the detector requirement from M to 2, while the requirement on measurement configurations is retained 2 M 3 − 2 M . To ensure physicality, maximum likelihood estimation is incorporated into the DQC1 reconstruction process, with numerical simulations demonstrating the efficiency of our approach and its robustness against interferometer noises. This method offers a resource-efficient solution for state characterization in large-scale LONs to advance photonic quantum technologies.