Measurements of a six dot HRL SLEDGE device from the Qubits for Computing Foundry

Spin qubits in electrically-defined Si/SiGe quantum dots are a promising platform for scalable quantum computers with very small footprints and recent progress in qubit number, coherence times, and fidelity. However, the small footprint leads to difficulties with consistent fabrication of these devices. In an effort to overcome this challenge, the Qubits for Computing Foundry offers semiconductor quantum devices for research projects that receive government funding. As a part of this Foundry program, we have received six-dot Si/SiGe devices from HRL. We have characterized these devices and explored the three-dot exchange-only qubit encoding, achieving 2-axis control, few us single shot readout, and have begun investigating the effects of gamma radiation on devices. Additionally, we are investigating the use of machine learning to automate tuning of these devices to maximize readout windows and signal-to-noise ratios (SNR). Production of reliable and reproducible devices from this Foundry program will pave the way for future developments in quantum computing.