Microwave spectroscopy system for molecules trapped in low temperature condensed media using opto-thermal detection with superconducting thin-film sensor

極低温マトリックス中における分子のマイクロ波分光のための超伝導薄膜センサーを用いた光熱変換検出分光システム

石黒 正純; 荒殿 保幸

Ishiguro, Masazumi; Aratono, Yasuyuki

量子凝縮相中における分子のマイクロ波分光のためのシンプルで応用範囲が広い分光システムを開発した。超電導薄膜センサーによる光熱変換検出法を用いることで、高感度かつシンプルなシステムが実現できた。テストとして固体パラ水素中のオルト水素対のスペクトルを観測し、S/N=8 のスペクトルが得られた。

Simple and widely applicable microwave spectroscopy system for the low temperature condensed media has been developed. We applied the technique of opto-thermal detection with superconducting thin-film sensor (STS) for the detection of very weak absorption signal of molecules trapped in quantum solid and liquid such as solid para-hydrogen (-H) and bulk liquid helium. For the test of the system, the microwave transition of ortho-hydrogen (-H) pair in solid -H was observed. The S/N ratio of the observed spectrum of the G transition at 1.4 K was approximately 8. Ultra high sensitivity of STS makes it possible not only to obtain sufficient sensitivity but also to make the apparatus very simple especially around the sample cell.