Controlling Quantum Interference via Non-Unitary Transformations in a 6-Mode Quantum Chip

Integrated photonic circuits are emerging as a flexible platform for advanced quantum information processing. In this work, we achieve precise and reproducible control of non-unitary transformations in a six-mode integrated photonic circuit. The system includes two independently tunable loss channels, which enable direct adjustment of the underlying dynamics. We use a singular value decomposition–based model to characterize two-photon non-unitary dynamics. Numerical simulations are then performed to examine how the loss channels affect the spatial distribution of the optical field. These results demonstrate a flexible method for controlling non-unitary optical systems and offer insights into the design of loss-engineered photonic devices and the development of advanced quantum information processing schemes.