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arXiv · 2610.03700

Scalable Passive QRAM

Siddhartha Jain·Alexander M. Dalzell·Connor T. Hann
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Abstract

We present a blueprint for implementing the physical QRAM operation in a scalable, passive manner, proving its feasibility in principle. Our construction is passive because for an $n$-qubit address over $N = 2^n$ memory bits the energy cost per QRAM query is $O(\log N)$, and to our knowledge it is the first construction to use $\operatorname{polylog} N$ energy. The runtime for each query is $O(\log^2 N)$. It is achieved by evolving a pre-manufactured time-independent 4-local Hamiltonian with $O(N)$ terms where every qubit participates in at most 4 terms.

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Siddhartha Jain, Alexander M. Dalzell, Connor T. Hann. 2026-10-02. Scalable Passive QRAM. https://arxiv.org/abs/2610.03700

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