Characterization of individual charge fluctuators in Si/SiGe quantum dots - Part II

Electron spins in silicon quantum dots are a promising quantum computing platform due to their long coherence times, scalability, and compatibility with advanced semiconductor technology. Even though single- and two-qubit gates with fidelities above 99% have been achieved in Si quantum dots, charge noise in the semiconductor environment still hinders gate fidelities, and key questions like what fluctuators cause charge noise, where they are in the device, and how they are thermalized, remain unanswered. Here, we probe individual two-level fluctuators (TLFs) in Si/SiGe quantum dots via simple quantum-dot transport measurements. We find that the TLF switching rates increase with temperature, and the current through the quantum dot appears to heat the TLFs. We also characterize the sensitivity of the TLFs to gate voltages. Altogether, our findings highlight the opportunities offered by semiconductor quantum dots to understand the origins of the TLFs.