Development of small mode volume phonon-photon coupled resonator for quantum transducer

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K13987
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13020:Semiconductors, optical properties of condensed matter and atomic physics-related
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: SASAKI Ryo 国立研究開発法人理化学研究所, 量子コンピュータ研究センター, 基礎科学特別研究員 (70890276)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 量子変換器 / オプトメカニクス / 表面弾性波 / 量子コンピュータ / 光変調器

Outline of Final Research Achievements

We have developed a microwave-optical signal transducer to realize an optically connected distributed superconducting quantum computer. In a method in which microwave and optical signals are converted using phonons as an intermediary, reducing the mode volume of phonon resonance is an effective way to increase the efficiency of the transducer. In this study, we developed a surface acoustic wave resonator on a piezoelectric thin film with a focusing wavefront. We achieved confinement of the surface acoustic wave resonance mode in the film thickness direction and within the surface, thereby achieving a small mode volume. We also investigated the design of the resonator and the properties of the thin film material. We clarified methods for controlling coupling with the resonance mode and reducing losses of the resonator.

Free Research Field

量子エレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

汎用な大規模量子コンピュータを実現するために，超伝導回路を含めた多くの方式において，光通信による接続方法が検討されている．本研究ではフォノンを利用した新しいデバイス構造に基づく変換器の開発を行い，変換器の高効率化のための要素技術の開発と，性能を制限している物理的な要因を明らかにした．ここで得られた知見は，特に圧電薄膜を用いた表面弾性波共振器の変換器への応用に貢献するものである．