arXiv Machine Learning

A Sim-to-Real Study of Surface-Code Decoder Benchmarking

The study benchmarks six quantum error‑correction decoders on the Willow processor, the first device operating below the surface‑code threshold, using a hierarchy of increasingly realistic noise models. By evaluating real hardware data across multiple code distances, bases, and round counts, the authors find that rank agreement with hardware emerges only when each operation type is assigned its own error rate. They also independently test NVIDIA’s Ising pre‑decoder, showing it offers no accuracy‑latency advantage over other decoders in most evaluations, and release the full evaluation pipeline and data for future comparisons.

arXiv AI
Jul 14

MDQEC-QAS: Meta-Decoding for Quantum Error Correction with Hardware-Aware VQC Search and Confidence-Gated Recovery

arXiv:2607. 10707v1 Announce Type: cross Abstract: We propose a unified meta-decoding framework for quantum error correction that learns syndrome-to-recovery mappings across multiple stabilizer codes and noise settings, without requiring separate decoders for each configuration.

By Prashant Kumar Choudhary, Nouhaila Innan, Muhammad Shafique, Rajeev Singh
arXiv AI
Sep 17

The Inference Engineering Pareto Atlas: Which Optimizations Dominate the Cost, Quality, and Latency Frontier?

The paper presents a Pareto atlas of LLM inference optimizations, mapping cost, quality, and latency trade‑offs for Qwen2.5‑7B‑Instruct on L4, A100, and H100 GPUs. Using 54 measured configurations and a calibrated simulator, it identifies 18 of 36 setups on the Pareto frontier, showing that combined methods outperform single ones. Quality tests reveal that AWQ 4bit and FP8 weights offer significant latency reductions while largely preserving accuracy, but naive FP8 KV caching fails to answer any questions correctly.

By Srikanta Datta Tumkur, Jay Iyer, Mehar Simhadri, Sai Pavan Kumar, Sai Kapil Kumar, Ramesh Nampelly
arXiv Machine Learning
Sep 7

Impact of Data Loss in Postprocessing on Training and Inference of Quantum Neural Networks

The paper investigates how postprocessing routines in quantum neural network software can cause significant data loss when run on large quantum hardware. In a case study of Qiskit’s “SamplerQNN”, a filter that assumes measurement bit‑strings are in virtual qubit space removed 85–99.6% of valid shots on IBM backends, leading to unnormalised probability vectors and distorted predictions. This loss caused inference accuracy to drop from 0.94 to 0.39 and compressed training loss signals by 22–27×, severely reducing optimizer sensitivity. The authors implemented a layout‑based marginalisation fix that was merged into the library to make “SamplerQNN” forward‑compatible with current and future hardware.

By Soraya V. Panambalom, Edoardo Altamura, Nick Chancellor, Jonte R. Hance
arXiv Machine Learning
Jul 15

VQCSim: When Does Compile-Once Statevector Simulation Beat Generic Quantum Frameworks?

arXiv:2607. 11985v1 Announce Type: cross Abstract: Hybrid quantum-classical machine learning workflows repeatedly evaluate many small parametrized circuits during training and model exploration.

By Anton Firc, Martin Pere\v{s}\'ini, Vojt\v{e}ch Mr\'azek, Kamil Malinka, Vojt\v{e}ch Stan\v{e}k, Zbyn\v{e}k Li\v{c}ka, Nouhaila Innan, Walid El Maouaki, Alberto Marchisio, Muhammad Shafique