Circuit Quantum Electrodynamics: A New Architecture for Superconducting Quantum Computation

Changhao Zhao, Yongcheng He, Geng Xiao +4 more

Abstract Resonators in circuit quantum electrodynamics systems naturally carry multiple modes, which may have non-negligible influence on qubit parameters and device performance. While new theories and techniques are under investigation to deal with the multi-mode effects in circuit quantum electrodynamics systems, novel engineering designs are also proposed featuring multi-mode resonators to achieve enhanced functionalities of superconducting quantum processors. In this work, multi-mode bus coupling architecture is proposed, in which superconducting qubits are coupled to multiple bus resonators to gain larger coupling strength. Application of multi-mode bus coupler can help improve iSWAP gate fidelity and gate speed beyond the limit of single-mode scenario. The proposed multi-mode bus coupling architecture is compatible with a scalable variation of the traditional bus coupling architecture. It opens up new possibilities for realization of scalable superconducting quantum computation with circuit quantum electrodynamics systems.

Leszek Jaroszynski

Changhao Zhao, Yongcheng He, Xiao Geng +4 more

Resonators in circuit quantum electrodynamics systems naturally carry multiple modes, which may have non-negligible influence on qubit parameters and device performance. While new theories and techniques are under investigation to deal with the multi-mode effects in circuit quantum electrodynamics systems, researchers have proposed novel engineering designs featuring multi-mode resonators to achieve enhanced functionalities of superconducting quantum processors. Here, we propose multi-mode bus coupling architecture, in which superconducting qubits are coupled to multiple bus resonators to gain larger coupling strength. Applications of multi-mode bus couplers can be helpful for improving iSWAP gate fidelity and gate speed beyond the limit of single-mode scenario. The proposed multi-mode bus coupling architecture is compatible with a scalable variation of the traditional bus coupling architecture. It opens up new possibilities for realization of scalable superconducting quantum computation with circuit quantum electrodynamics systems.

Jason F. Ralph, R. Whiteman, J. Diggins +5 more

Mahn‐Soo Choi

Abstract The quantum coherent behaviors of superconducting devices at macroscopic scales and recent technical advances in fine tunability have brought the conventional cavity quantum electrodynamics (QED) to superconducting circuits. With an ultra‐strong cavity photon–artificial atom coupling and the inherent nonlinearity of the Josephson junctions, the so‐called circuit QED offers new opportunities to explore new realms of physics that have remained a challenge for conventional cavity QED. Circuit QED has even attracted public attention as the leading architecture for quantum computation. In this article, a pedagogical review of recent studies and activities on exotic quantum states that can be attributed to ultra‐strong coupling is provided. A progress report on attempts to seek the smallest unit of the topological matter and its fundamental interaction with light is also provided.

Hakan E. Türeci