Progress Towards Multispecies Three-Node Quantum Network

Trapped ions are one of the leading platforms for quantum technologies including simulations, computing, sensing, metrology, and networking. Quantum networking enables scaling of ion-trap-based quantum computers, where individual ion chains in separate traps can be entangled via photonic interconnects. Here we report our progress towards a quantum network consisting of three multispecies ion traps in separate vacuum chambers. Each node of the network contains barium ions for remote entanglement generation and nearby ytterbium ions for quantum memory. Using different species avoids crosstalk between communication and memory qubits and allows us to benefit from individual strengths of each ion species. Barium is well-suited for communications since it emits single photons in the visible range of the electromagnetic spectrum. Ytterbium features long coherence times allowing for long-lasting quantum memory. This approach offers potential for the creation of larger quantum networks for quantum computing scaling, quantum communications and other applications of quantum technologies.