Distributed quantum computing across an optical network link

Area of Science:

• Quantum Information Science
• Quantum Computing
• Quantum Networking

Background:

• Distributed quantum computing (DQC) aims to enhance computational power by networking quantum processing modules.
• Photonic networks offer a reconfigurable interconnect for DQC, enabling logical connectivity via quantum gate teleportation (QGT).
• Deterministic and repeatable QGT is crucial for scalable DQC architectures but has been previously unachieved.

Purpose of the Study:

• To experimentally demonstrate the distribution of quantum computations between photonically interconnected trapped-ion modules.
• To achieve deterministic quantum gate teleportation for scalable DQC.
• To implement distributed quantum algorithms and operations.

Main Methods:

• Utilized two trapped-ion modules separated by approximately two meters, each with dedicated network and circuit qubits.
• Employed heralded remote entanglement between network qubits to deterministically teleport a controlled-Z (CZ) gate.
• Executed Grover's search algorithm and distributed iSWAP/SWAP circuits using multiple instances of QGT.

Main Results:

• Achieved 86% fidelity in deterministic teleportation of a CZ gate between circuit qubits in separate modules.
• Demonstrated a 71% success rate for Grover's search algorithm, the first distributed quantum algorithm with non-local gates.
• Successfully implemented distributed iSWAP and SWAP circuits, showcasing the distribution of arbitrary two-qubit operations.

Conclusions:

• The demonstrated DQC architecture provides a viable pathway towards large-scale quantum computing.
• Deterministic QGT using photonic interconnects is achievable in trapped-ion systems.
• This approach supports a range of physical platforms for future quantum computing advancements.