Engineering Noise-Protected Superconducting Qubits

Abstract

Improving the lifetime of qubits is crucial to achieve reliable quantum computation with superconducting qubits. One way to improve the qubit lifetime is to engineer the circuit design and the parameters to protect the qubit from environmental noise. Some of the noise-protected superconducting qubits have the potential to overcome the coherence limitations of transmons, which is often dominated by energy relaxation. Here we study the zero-pi qubit, the superconducting circuit-based qubit that can provide simultaneous protection against dephasing and relaxation. Although the noise-protection property of the zero-pi qubit is appealing, it has stricter design parameter constraints than other superconducting qubits and the coherent control of the qubit is challenging. In this thesis, we propose several methods to enable fast, robust control in the zero-pi qubit. Additionally, we introduce some preliminary measurement results of the zero-pi qubit and discuss how to mitigate the challenges we faced during the measurement.