Scalable Connection of Qubits to Quantum Error Correction Systems using Ethernet

Large-scale quantum computing requires quantum error correction to address the inherent instability of physical qubits. Recent advancements demonstrate that quantum error correction can reduce the logical error rate, paving the way for fault-tolerant quantum computers. However, significant challenges remain in scaling up to large devices.

This talk examines data communication between qubits and the classical hardware that runs the error correction decoders. We present a scalable method for connecting multiple qubit control boxes to error decoders using dedicated Ethernet networks [1]. Intermediate aggregation units placed between control boxes and error decoders enable the transfer of syndrome data for 95 logical qubits encoded in a distance-41 surface code over standard 400-gigabit networks. This approach achieves the necessary data transfer for superconducting qubits, assuming 500 ns per round of syndrome extraction, while keeping network latency below 2 μs.

Our method also enables the integration of equipment from different vendors, allowing for flexibility in building quantum computers.

[1] J.-E. R. Wichmann, K. Sano, “Connecting Physical Qubits to Quantum Error Correction Backends using Regular Ethernet”, 2024 IEEE Int. Conf. on Quantum Comput. and Eng. (QCE), in press