Reconstructing Quantum Dot Charge Stability Diagrams with Diffusion Models
This work addresses a critical bottleneck in scaling quantum processors by reducing characterization overhead for quantum devices, though it is incremental as it applies an existing generative method to a new domain-specific problem.
The authors tackled the time-consuming problem of measuring high-resolution charge stability diagrams (CSDs) for quantum dot devices by using a conditional diffusion model to reconstruct full CSDs from sparse measurements, achieving successful reconstruction from as little as 4% of the total data while maintaining key physical features like charge transition lines.
Efficiently characterizing quantum dot (QD) devices is a critical bottleneck when scaling quantum processors based on confined spins. Measuring high-resolution charge stability diagrams (or CSDs, data maps which crucially define the occupation of QDs) is time-consuming, particularly in emerging architectures where CSDs must be acquired with remote sensors that cannot probe the charge of the relevant dots directly. In this work, we present a generative approach to accelerate acquisition by reconstructing full CSDs from sparse measurements, using a conditional diffusion model. We evaluate our approach using two experimentally motivated masking strategies: uniform grid-based sampling, and line-cut sweeps. Our lightweight architecture, trained on approximately 9,000 examples, successfully reconstructs CSDs, maintaining key physically important features such as charge transition lines, from as little as 4\% of the total measured data. We compare the approach to interpolation methods, which fail when the task involves reconstructing large unmeasured regions. Our results demonstrate that generative models can significantly reduce the characterization overhead for quantum devices, and provides a robust path towards an experimental implementation.