Sam McArdle

dblp:339/8793 · DBLP profile ↗
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1ranked-venue papers
0as first author
1since 2021 · last 2025
—ORCID · unresolved

Domains — the database's venue-derived domains; a paper can count in several

Theory of computation · 1 · 1 since 2021

Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.

Theoretical computer science
1 paper
Quantum computing and quantum information · 100%
Computer architecture, parallel and distributed computing, and storage systems
1 paper
Emerging computing paradigms · 100%

Topics — the 5 heaviest of 5, each with the papers that count most for it

TopicWeightPapersLastEvidence papers
Emerging computing paradigms
quantum computer architecture
0.912025
A Distillation-Teleportation Protocol for Fault-Tolerant QRAM · FOCS 2025
Emerging computing paradigms › quantum computer architecture
quantum random access memory
0.912025
A Distillation-Teleportation Protocol for Fault-Tolerant QRAM · FOCS 2025
Quantum computing and quantum information › quantum error correction
fault-tolerant quantum computation
0.912025
A Distillation-Teleportation Protocol for Fault-Tolerant QRAM · FOCS 2025
Quantum computing and quantum information
quantum algorithms
0.912025
A Distillation-Teleportation Protocol for Fault-Tolerant QRAM · FOCS 2025
Quantum computing and quantum information
quantum error correction
0.912025
A Distillation-Teleportation Protocol for Fault-Tolerant QRAM · FOCS 2025

Methods — techniques the papers use, named apart from their topics

teleportation · 1.7quantum purity amplification · 1.7quantum error correction · 1.7distillation · 1.7
YearPublicationVenuePosition
2025 A Distillation-Teleportation Protocol for Fault-Tolerant QRAM
abstract
We present a protocol for fault-tolerantly implementing the logical quantum random access memory (QRAM) operation, given access to a specialized, noisy QRAM device. For coherently accessing classical memories of size $2^{n}$, our protocol consumes only poly $(n)$ fault-tolerant quantum resources (logical gates, logical qubits, quantum error correction cycles, etc.), avoiding the need to perform active error correction on all $\Omega\left(2^{n}\right)$ components of the QRAM device. This is the first rigorous conceptual demonstration that a specialized, noisy QRAM device could be useful for implementing a fault-tolerant quantum algorithm. In fact, the fidelity of the device can be as low as $1 / \operatorname{poly}(n)$. The protocol queries the noisy QRAM device $\operatorname{poly}(n)$ times to prepare a sequence of n-qubit QRAM resource states, which are moved to a general-purpose poly $(n)$ size processor to be encoded into a QEC code, distilled, and faulttolerantly teleported into the computation. To aid this protocol, we develop a new gate-efficient streaming version of quantum purity amplification that matches the optimal sample complexity in a wide range of parameters and is therefore of independent interest. The exponential reduction in fault-tolerant quantum resources comes at the expense of an exponential quantity of purely classical complexity-each of the n iterations of the protocol requires adaptively updating the $2^{n}$-size classical dataset and providing the noisy QRAM device with access to the updated dataset at the next iteration. We show that this classical operation can be parallelized to poly $(n)$ classical circuit depth, but only in a model where classical sparse matrix-vector multiplication for $2^{n}$-dimensional vectors can be as well. While our protocol demonstrates that QRAM is more compatible with fault-tolerant quantum computation than previously thought, the need for significant classical computational complexity exposes potentially fundamental limitations to realizing a truly poly $(n)$-cost faulttolerant QRAM.
Alexander M. Dalzell, András Gilyén, Connor T. Hann, Sam McArdle, Grant Salton, Quynh T. Nguyen, Aleksander Kubica, Fernando G. S. L. Brandão
FOCS4