Pulse Design for Two-Qubit Gates in Superconducting Circuits

Abstract

Despite tremendous progress towards achieving low error rates with superconducting qubits, error-prone two-qubit gates remain a bottleneck in realizing large-scale quantum computers. To boost the two-qubit gate fidelity to the highest attainable levels given limited coherence time, it is essential to develop a systematic framework to optimize protocols for implementing two-qubit gates. In this thesis, we formulate the design of the control trajectory for baseband controlled phase gates in superconducting circuits into a pulse design problem. Our research indicates that the Chebyshev trajectories – the trajectories based on the Chebyshev pulse and weighted Chebyshev approximation – have the potential to outperform the Slepian trajectories based on the Slepian pulse, which are currently widely used in quantum experiments.