Quantum control and process tomography of a semiconductor quantum dot hybrid qubit

First experimental universal control and process tomography of the Si/SiGe quantum-dot hybrid qubit.

Key Results

Demonstrates sub-100-ps rotations about two Bloch-sphere axes in a three-electron double dot.
Reports process fidelities of 85-89% for the measured $X$ rotations and 94-96% for the measured $Z$ rotations.
Measures $T_{2}^{*} \approx 2$ ns in the charge-like regime and $T_{2}^{*} \approx 10$ ns for spin-like phase evolution.