Superconducting qubits are among the leading competitors in the race towards building the first full-fledged quantum computer. Using this platform, researchers have for the first time demonstrated computational capability that is beyond the reach of the current classical machines. (This achievement is nicknamed "Quantum Supremacy".) Up to date, however, the performance of superconducting quantum processors still fails to fully satisfy the requirement for efficient and useful quantum computation, which is largely due to their decoherence induced by the environmental noise. The challenge posed by the noise motivates researchers to put intensive efforts into understanding, mitigating and even leveraging the noise that affects superconducting qubits. In this thesis, we will discuss several strategies that we have developed recently for both noise engineering and mitigation in superconducting qubits. Specifically, we present a strategy based on the tunable coupling between a qubit and a noisy ancilla to universally stabilize the former in arbitrary single-qubit states. For noise mitigation, we propose a scheme based on dynamical sweet spots to protect superconducting qubits from the ubiquitous and detrimental 1/f noise. Using this framework, we further introduce a novel qubit design, the revolver qubit, which is predicted to enjoy protection from both dephasing due to 1/f noise and depolarization.

Creator

• Huang, Ziwen

DOI

• https://doi.org/10.21985/n2-zk85-2g03

Subject

• Physics
• Quantum physics
• Condensed matter physics

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:15760
• etdadmin_upload_845242

Keyword

• Superconducting Qubit
• Protected Qubit
• Noise Engineering
• Dynamical Sweet Spot

Date created

• 2021-01-01

Resource type

• Dissertation

Rights statement

• In Copyright