AQP Seminar: Superconducting Kerr Parametric Oscillators based Bosonic Qubit
Speaker: Prof. Jaw-Shen Tsai (National Yang Ming Chiao Tung University, Riken Center for Quantum Computing)
Host: Prof. Jukka Pekola
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Superconducting Kerr Parametric Oscillators based Bosonic Qubit
Prof. Jaw-Shen Tsai (National Yang Ming Chiao Tung University, Riken Center for Quantum Computing)
Abstract: Utilizing superconducting Kerr parametric oscillators (KPOs), we successfully carried out X-gate and Z gate operations [1]. Moreover, the similar approach enables us to entangle a pair of Schrödinger’s cat states by two methods. The first involves the entanglement-preserving conversion between Bell states in the Fock-state basis and those in the cat-state basis. The second method implements a gate between two cat states following the procedure for Fock-state encoding. This simple and fast gate operation completes a universal quantum gate set in a KPO system [2]. We also implemented a three-photon KPO and explore its potential as a protected bosonic qutrit. We confirmed quantum coherence by demonstrating three-photon Rabi oscillations and performing direct Wigner function measurements that revealed the formation of three-component catlike states [3].
References:
[1] D. Iyama, et al. “Observation and manipulation of quantum interference in a superconducting Kerr parametric oscillator”. Nat Commun 15, 86 (2024).
[2] Daisuke Hoshi, et al, “Entangling Schrödinger’s cat states by bridging discrete- and continuous-variable encoding”, Nature Communications 16, 1309 (2025)
[3] Sangil Kwon, et al, “Realization of a Protected Cat-Qutrit Manifold via Engineered Quantum Tunnelling”, arXiv:2601.17675, to be published in Nature Cmmunication.
This event is supported by InstituteQ, Finland's National Quantum Institute.