Graduate Program Events
Semiconductor qubits offer a promising platform that can be readily expanded by leveraging existing semiconductor industry facilities. In semiconductor devices, an array of detrimental noise sources, such as charge noise, hyperfine noise, evanescent-wave Johnson noise, and phonon-induced noise, can degrade coherence of the qubits. This dissertation specifically focuses on charge noise (1/f noise).
The dissertation commences by introducing a methodology to characterize diverse noise sources through the measurement of coherence times while rotating a vector magnet in a spin qubit device. Subsequently, it presents the application of a technique called noise source driving to enhance coherence of qubits. This approach involves applying an oscillating electric field to the charge noise sources. Following this, the dissertation elucidates a plausible mechanism explaining the pulse-induced resonance frequency shift of a qubit with fluctuations of two-level systems. Lastly, the dissertation discusses future research directions and concludes with closing remarks