Beyond the T1 limit:: Singlet nuclear spin states in low magnetic fields -: art. no. 153003
Beyond the T1 limit:: Singlet nuclear spin states in low magnetic fields -: art. no. 153003
复制标题
DOI：
10.1103/physrevlett.92.153003
复制
发表时间：
2004-04-16
影响因子：
8.6
通讯作者：
Levitt, MH
中科院分区：
文献类型：
--
作者：
Carravetta, M;Johannessen, OG;Levitt, MH
低场核自旋单重态可以用来在室温液体中储存比自旋晶格弛豫时间常数T-1长得多的时间。低场核自旋单重态不受分子内偶极子-偶极子弛豫的影响，偶极子-偶极子弛豫通常是主要的弛豫机制。我们证明了核自旋序的存储时间比T-1的测量值长10倍以上。这种现象可以促进核自旋超极化方法的发展，并可以研究现有核磁共振技术发生太慢的运动过程。这是第一次，核自旋的记忆已经扩展到远远超过T-1极限，在一个系统缺乏内在的磁等效。
Low-field nuclear spin singlet states may be used to store nuclear spin order in a room temperature liquid for a time much longer than the spin-lattice relaxation time constant T-1. The low-field nuclear spin singlets are unaffected by intramolecular dipole-dipole relaxation, which is generally the predominant relaxation mechanism. We demonstrate storage of nuclear spin order for more than 10 times longer than the measured value of T-1. This phenomenon may facilitate the development of nuclear spin hyperpolarization methods and may allow the study of motional processes which occur too slowly for existing NMR techniques. This is the first time that the memory of nuclear spins has been extended well beyond the T-1 limit in a system lacking intrinsic magnetic equivalence.