Improvement of an accuracy of optical frequency standard using the 115In+ ion sympathetically cooled by the 171Yb+ ion

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K20362
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0202:Condensed matter physics, plasma science, nuclear engineering, earth resources engineering, energy engineering, and related fields
• Research Institution: National Institute of Information and Communications Technology
• Principal Investigator: KIHARA Ami 国立研究開発法人情報通信研究機構, 電磁波研究所電磁波標準研究センター, 研究員 (90911371)
• Project Period (FY): 2021-08-30 – 2024-03-31
• Keywords: イオントラップ / 光周波数標準

Outline of Final Research Achievements

To improve the accuracy of an indium ion trap optical clock which has been already developed in our group, we started to construct a new indium ion trap optical clock system. In the new system, we used a single ytterbium ion to cool an indium ion sympathetically. This is because a mass ratio between a cooling ion and a coolant ion should be nearly unity to effectively cool.
During the term of the research, we constructed a new ion trap system including some laser systems. After that, we succeeded in trapping a single ytterbium ion and a single indium ion in the trap together. We also developed a 230nm laser system to be able to detect indium ion quantum state for the clock frequency measurement. We tested laser frequency locking and confirmed it kept stable operation over 3 hours.

Free Research Field

量子エレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

インジウムイオン光時計は様々なイオン種が提案されているイオントラップ光時計の中でも環境によるずれの影響を受けにくく精度の良い時計としてその将来性が期待されている。また、イオントラップ光時計は量子ネットワークとの親和性も持っていることから、将来的に量子インターネットに光時計を組み込むことも可能であり、より安全かつ高精度な時刻同期にも期待が持てる。本研究成果はその始めの一歩を踏み出したと言える。