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arXiv · 2503.19172

Resource-state Quantum RAM for Fast and Error-Correctable Queries

Francesco Cesa·Hannes Bernien·Hannes Pichler
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Abstract

Quantum devices can process data in a fundamentally different way than classical computers. To leverage this potential, many algorithms require the aid of a quantum Random Access Memory (QRAM), i.e. a module capable of efficiently loading datasets onto the quantum processor. However, a realisation of this building block is still outstanding due to its formidable resource requirements, which become even more demanding in quantum error-correction schemes. Here we show that the challenge of implementing QRAM can be entirely reduced to a state-preparation problem: since such resource-state is independent on the memory, our approach allows one to prepare it offline, opening the door to new design strategies. As an example, we introduce a heralded 'QRAM factory' which enables improved fidelities with high acceptance rate. More broadly, our results introduce the concept of resource-state QRAM: we study its performance in noisy settings, showing that it preserves the noise-resilience of standard QRAM, and discuss how it can be efficiently combined with quantum error-correction. Finally, we propose an implementation with neutral-atom hardware, where our analysis suggests that high-fidelity and low-latency queries can be implemented.

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Francesco Cesa, Hannes Bernien, Hannes Pichler. 2025-03-24. Resource-state Quantum RAM for Fast and Error-Correctable Queries. https://doi.org/10.1038/s41467-026-73275-x

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