Experimental Perfect Quantum State Transfer

The transfer of data is a fundamental task in information systems. Microprocessors contain dedicated data buses that transmit bits across different locations and implement sophisticated routing protocols. Transferring quantum information with high fidelity is a challenging task, due to the intrinsic fragility of quantum states. We report on the implementation of the perfect state transfer protocol applied to a photonic qubit entangled with another qubit at a different location. On a single device we perform three routing procedures on entangled states with an average fidelity of 97.1%. Our protocol extends the regular perfect state transfer by maintaining quantum information encoded in the polarisation state of the photonic qubit. Our results demonstrate the key principle of perfect state transfer, opening a route toward data transfer for quantum computing systems.