High-rate Generation and State Tomography of Non-Gaussian Quantum States for Ultra-fast Clock Frequency Quantum Processors

• DOI: 10.48550/arxiv.2402.17408
• Publication Date: 2024-02-27
• Authors: Akito Kawasaki; Ryuhoh Ide; Hector Brunel; Takumi Suzuki; Rajveer Nehra; Katsuki Nakashima; Takahiro Kashiwazaki; Asuka Inoue; Takeshi Umeki; Fumihiro China; Masahiro Yabuno; Shigehito Miki; Hirotaka Terai; Taichi Yamashima; A. Sakaguchi; Kan Takase; Mamoru Endo; Warit Asavanant; Akira Furusawa
• Keywords: Quantum tomography; Clock rate

Quantum information processors greatly benefit from high clock frequency to fully harnessing the quantum advantages before they get washed out by decoherence. In this pursuit, all-optical systems offer unique due their inherent 100 THz carrier frequency, permitting one develop processors. practice, bandwidth of light sources and measurement devices has been limited MHz range generation rate nonclassical states kHz order -- a tiny fraction what can be achieved. work, we go beyond limitation utilizing optical parametric amplifier (OPA) as squeezed-light source phase-sensitive amplifiers (PSA) realize high-rate broadband non-Gaussian tomography. Our state system consists 6-THz source, PSA, 66-GHz homodyne detector. With system, have successfully demonstrated at 0.9 almost three orders magnitude higher than current state-of-the-art experiments with sub-nanosecond wave packet using continuous-wave laser. The performance is constrained only superconducting detector's jitter which currently limits usable squeezed 1 GHz, rather electronic systems. Therefore, if overcome timing detector, detection GHz rate, or even for might possible OPAs.