Modular Autonomous Virtualization System for Two-Dimensional Semiconductor Quantum Dot Arrays

TL;DR

This paper introduces MAViS, a machine learning-based modular system that automates the creation of virtual gates for large-scale 2D quantum dot arrays, enabling precise control essential for quantum computing.

Contribution

The paper presents a novel automated framework that uses machine learning and computer vision to accurately determine capacitive couplings for virtual gates in quantum dot arrays.

Findings

Successfully virtualized a 10-dot array in Ge/SiGe heterostructure.

Achieved real-time, accurate control of quantum dot parameters.

Demonstrated effectiveness in both low- and high-tunnel-coupling regimes.

Abstract

Arrays of gate-defined semiconductor quantum dots are among the leading candidates for building scalable quantum processors. High-fidelity initialization, control, and readout of spin qubit registers require exquisite and targeted control over key Hamiltonian parameters that define the electrostatic environment. However, due to the tight gate pitch, capacitive crosstalk between gates hinders independent tuning of chemical potentials and interdot couplings. While virtual gates offer a practical solution, determining all the required cross-capacitance matrices accurately and efficiently in large quantum dot registers is an open challenge. Here, we establish a modular automated virtualization system (MAViS) -- a general and modular framework for autonomously constructing a complete stack of multilayer virtual gates in real time. Our method employs machine learning techniques to rapidly extract features from two-dimensional charge stability diagrams. We then utilize computer vision and regression models to self-consistently determine all relative capacitive couplings necessary for virtualizing plunger and barrier gates in both low- and high-tunnel-coupling regimes. Using MAViS, we successfully demonstrate accurate virtualization of a dense two-dimensional array comprising ten quantum dots defined in a high-quality Ge/SiGe heterostructure. Our work offers an elegant and practical solution for the efficient control of large-scale semiconductor quantum dot systems.