Non-Hermitian unidirectional routing of photonic qubits

This study employs a non-Hermitian process that effectively balances coherent and dissipative channels, ensuring the unidirectional transfer of photonic qubits. The significance of this approach lies in its applicability to unidirectional routing in both the classical and quantum domains, which is currently challenging to achieve in the synthesis of qubit unidirectional routers and spin-wave diodes. Additionally, this system's fully optical tunable properties can reverse the direction of qubit transfer. This scheme is expected to greatly impact the design of unidirectional devices in quantum communication and information processing.