Spatial distribution of charge defects in semiconductor quantum dot devices

Ascertain the spatial distribution of Coulomb-type charge defects in semiconductor quantum dot devices hosting planar Ge hole spin qubits, specifically determining how traps are positioned across the device plane relative to the quantum dot and interfaces, in order to enable realistic modeling of 1/f charge noise from individual fluctuators.

Background

The paper models dephasing from 1/f charge noise by building up an ensemble of random telegraph noise sources from individual Coulomb-type charge defects. While the analysis adopts a planar defect distribution consistent with typical device layouts, the authors note that the actual spatial distribution of charge traps remains experimentally unresolved.

Understanding the spatial distribution is essential because the dephasing calculation requires averaging fluctuations in the qubit Zeeman splitting over defect positions. A realistic distribution informs the defect density and distance-dependent coupling to the quantum dot, which directly affects the inferred 1/f noise spectrum and T2*.