Infrared absorption spectroscopy of a single polyatomic molecular ion

• 成果类型: Article
• 署名作者: Wu, Zhenlin; Duka, Tim; Isaza-Monsalve, Mariano; Kautzky, Miriam; Svarc, Vojtech; Turci, Andrea; Nardi, Rene; Gronowski, Marcin; Tomza, Michal; Furey, Brandon J.; Schindler, Philipp
• 署名单位: University of Innsbruck; Palacky University Olomouc; University of Warsaw
• 刊物名称: NATURE
• ISSN/ISSBN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-026-10915-8
• 发表日期: 2026-09-10
• 关键词: BASIS-SET CONVERGENCE; pure quantum states; entanglement; manipulation

摘要

Absorption spectroscopy is a fundamental tool for probing molecular structure1. However, performing absorption spectroscopy on individual molecules is challenging because of the low signal-to-noise ratio2,3. Here we report on non-destructive absorption spectroscopy on a mid-infrared vibrational transition in a single molecular ion that is co-trapped with an atomic ion. The absorption of a single photon is detected by the momentum transfer from the absorbed photon onto the molecule. This recoil signal is amplified using a non-classical state of motion of the two-ion crystal and subsequently read out by the atomic ion4. We characterize the recoil detection method and use it to investigate the interaction between femtosecond laser pulses and the O-H stretching vibration in individual CaOH+ molecular ions. Furthermore, we present the spectrum obtained for the vibrational transition with single-photon sensitivity. This method can provide a way of performing non-destructive state detection of complex polyatomic molecules, for preparation and measurement of the quantum state of a wide range of molecular species.