Constant-Rate Entanglement Distillation for Fast Quantum Interconnects

Abstract

Distributed quantum computing allows the modular construction of large-scale quantum computers and enables new protocols for blind quantum computation. However, such applications in the large-scale, fault-tolerant regime place stringent demands on the fidelity and rate of entanglement generation, which are not met by existing methods for quantum interconnects. In this work, we develop constant-rate entanglement distillation methods to address this bottleneck in the setting of noisy local operations. By using a sequence of two-way entanglement distillation protocols based on quantum error detecting codes with increasing rate, and combining with standard fault tolerance techniques, we achieve constant-rate entanglement distillation. We show that the scheme has constant-rate in expectation, and further numerically optimize to achieve low practical overhead under memory constraints. We find that compared to existing quantum interconnect schemes, our methods reduce the communication overhead by more than 10 × in relevant regimes, leading to a direct speed-up in the execution of distributed quantum algorithms.