Universal long-time behavior of nuclear spin decays in a solid.
Universal long-time behavior of nuclear spin decays in a solid.
复制标题
核自旋的普遍长期行为在固体中衰变。
DOI：
10.1103/physrevlett.101.067601
复制
发表时间：
2008
影响因子：
8.6
通讯作者：
Brian Saam
中科院分区：
文献类型：
--
作者：
Steven W. Morgan;Boris V. Fine;Brian Saam
对固体中核自旋的磁共振研究非常适合于探索统计物理的极限。我们报告的实验结果表明，相互作用的核自旋的孤立的宏观系统具有以下基本属性：自旋衰变，从不同的初始配置迅速演变到相同的长时间的行为。这种长时间行为的特点是最短的弹道微观时间尺度的系统，因此福尔斯的有效性范围外的传统近似的统计物理。我们发现超极化固态氙的核自由感应衰减和不同的固态回波都表现出正弦调制的指数长时间行为，其特征在于具有相同的时间常数。这种普遍性是以前预测的基础上的类比与共振在经典的混沌系统。
Magnetic resonance studies of nuclear spins in solids are exceptionally well suited to probe the limits of statistical physics. We report experimental results indicating that isolated macroscopic systems of interacting nuclear spins possess the following fundamental property: spin decays that start from different initial configurations quickly evolve towards the same long-time behavior. This long-time behavior is characterized by the shortest ballistic microscopic time scale of the system and therefore falls outside of the validity range for conventional approximations of statistical physics. We find that the nuclear free-induction decay and different solid echoes in hyperpolarized solid xenon all exhibit sinusoidally modulated exponential long-time behavior characterized by identical time constants. This universality was previously predicted on the basis of analogy with resonances in classical chaotic systems.