Studying Valley Splitting in an Industrially Manufactured Quantum Dot Array

Quantum dots in Si/SiGe heterostructures are a promising solid state quantum computing platform. However, a more complete understanding of the relationship between the underlying material and the emergent qubit properties is necessary to realize the promise of the scalable technology. Namely, recent work has studied the relationship between alloy disorder in the material and the low-lying valley energies of the quantum dot. These valley states impact qubit fidelity; however, engineering large valley splitting requires accurate understanding of the underlying cause of valley splitting in real-world devices. Here, we use detuning axis pulsed spectroscopy (DAPS) to measure valley splitting in many dots along 1.3μm of a 2DEG channel in an industrially fabricated 1D quantum dot array. We observe a variation in valley splitting versus position and corroborate this behavior with device simulations and theoretical predictions. The improved understanding of valley physics will inform future device operation and fabrication.