Extremely Low-Frequency Spectroscopy in Low-Field Nuclear Magnetic Resonance
Extremely Low-Frequency Spectroscopy in Low-Field Nuclear Magnetic Resonance
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DOI：
10.1103/physrevlett.103.083002
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发表时间：
2009-08-21
影响因子：
8.6
通讯作者：
Levitt, Malcolm H.
中科院分区：
文献类型：
--
作者：
Pileio, Giuseppe;Carravetta, Marina;Levitt, Malcolm H.
我们展示了核磁共振波谱中的一种新现象，其中核自旋跃迁是由极低频率（几赫兹数量级）的射频辐射引起的。在不同交换对称性的自旋态之间观察到慢拉比振荡。这些“禁止的”跃迁由于射频场上的差分电子屏蔽效应而变得微弱地允许。我们在溶液中生成 N-15 标记的一氧化二氮的单重态和三重态之间的相干性，并以几 mHz 的精度估计两个 N-15 核之间的标量耦合。
We demonstrate a new phenomenon in nuclear magnetic resonance spectroscopy, in which nuclear spin transitions are induced by radio frequency irradiation at extremely low frequencies (of the order of a few Hz). Slow Rabi oscillations are observed between spin states of different exchange symmetry. These "forbidden" transitions are rendered weakly allowed by differential electronic shielding effects on the radio frequency field. We generate coherence between the singlet and triplet states of N-15-labeled nitrous oxide in solution, and estimate the scalar coupling between the two N-15 nuclei with a precision of a few mHz.