Qubit Rate Modulation-Based Time Synchronization Mechanism for Multinode Quantum Networks

The combination of quantum and telecommunication networks enables to revolutionize the way information is used, offering unparalleled capabilities and making it an ideal choice for many critical applications. In this sense, quantum protocols generally have a unique requirement to have strict time synchronization in order to operate, which generally consume quantum resources of part of the exchanged qubits. Accordingly, work demonstrates and characterizes a temporal alignment mechanism for quantum networks based on frequency testing, allowing to preserve the quantum state of qubits. The time synchronization correction achieved is within 100 ns working at 5 MHz with temporal and relative frequency offsets commonly acquired in quantum links using conventional hardware clocks with temporal stability in the range of $10^{-8}$ and 200-ns jitter.