Colloquium: Dr. Ziwen Huang | SQMS Center
In-Person PHYS 401
Location
Physics : 401
Date & Time
March 27, 2024, 11:00 am – 12:00 pm
Description
TITLE: "Tackling noise in superconducting qubits”
ABSTRACT: Superconducting qubits are among the leading candidates for building full-stack quantum computers. This type of quantum platform has attracted a significant amount of attention and investment from both academia and industry. However, practical applications are hindered by low gate fidelities due to excessive noise. In this talk, I will focus on several recent theoretical innovations that help suppress noise in superconducting qubits and beyond. Specifically, I will first introduce a new noise-mitigation approach based on Floquet engineering using periodic drives [1]. The emergent dynamical sweet spots not only offer protection from low-frequency 1/f noise but also afford greater flexibility for engineering versatile entangling gates for superconducting qubits. This noise mitigation strategy has been recently extended to a higher-order framework [2]. Furthermore, I will explore the extension of Floquet techniques to scenarios involving non-periodic drives [3]. This more systematical approach, based on Keldysh diagrams, handle arbitrary drive pulses and complex noise backgrounds. We demonstrate that leveraging the Keldysh-based methods, in combination with quantum optimal control techniques, enables the automatic generation of pulses to circumvent resonances in the noise background. These efforts lay the basis for further enhancing gate fidelities on superconducting qubits, paving the way for practical quantum applications in the future. [1] Huang et al., Phys. Rev. Appl. 15, 034065 (2021); [2] Huang et al., Phys. Rev. Appl. 18, L061001 (2022); [3] Huang et al., Quantum 7, 1158 (2023).
ABSTRACT: Superconducting qubits are among the leading candidates for building full-stack quantum computers. This type of quantum platform has attracted a significant amount of attention and investment from both academia and industry. However, practical applications are hindered by low gate fidelities due to excessive noise. In this talk, I will focus on several recent theoretical innovations that help suppress noise in superconducting qubits and beyond. Specifically, I will first introduce a new noise-mitigation approach based on Floquet engineering using periodic drives [1]. The emergent dynamical sweet spots not only offer protection from low-frequency 1/f noise but also afford greater flexibility for engineering versatile entangling gates for superconducting qubits. This noise mitigation strategy has been recently extended to a higher-order framework [2]. Furthermore, I will explore the extension of Floquet techniques to scenarios involving non-periodic drives [3]. This more systematical approach, based on Keldysh diagrams, handle arbitrary drive pulses and complex noise backgrounds. We demonstrate that leveraging the Keldysh-based methods, in combination with quantum optimal control techniques, enables the automatic generation of pulses to circumvent resonances in the noise background. These efforts lay the basis for further enhancing gate fidelities on superconducting qubits, paving the way for practical quantum applications in the future. [1] Huang et al., Phys. Rev. Appl. 15, 034065 (2021); [2] Huang et al., Phys. Rev. Appl. 18, L061001 (2022); [3] Huang et al., Quantum 7, 1158 (2023).
