Sánchez Claudia M, Buljubasich Lisandro, Pastawski Horacio M, Chattah Ana K
Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba, X5016LAE Córdoba, Argentina.
Facultad de Matemática, Astronomía, Física y Computación, Universidad Nacional de Córdoba, X5016LAE Córdoba, Argentina; IFEG - CONICET, X5016LAE Córdoba, Argentina.
J Magn Reson. 2017 Aug;281:75-81. doi: 10.1016/j.jmr.2017.05.009. Epub 2017 May 20.
In this article, we introduce a pulse sequence which allows the monitoring of multiple quantum coherences distribution of correlated spin states developed with scaled dipolar Hamiltonian. The pulse sequence is a modification of our previous Proportionally Refocused Loschmidt echo (PRL echo) with phase increment, in order to verify the accuracy of the weighted coherent quantum dynamics. The experiments were carried out with different scaling factors to analyze the evolution of the total magnetization, the time dependence of the multiple quantum coherence orders, and the development of correlated spins clusters. In all cases, a strong dependence between the evolution rate and the weighting factor is observed. Remarkably, all the curves appeared overlapped in a single trend when plotted against the self-time, a new time scale that includes the scaling factor into the evolution time. In other words, the spin system displayed always the same quantum evolution, slowed down as the scaling factor decreases, confirming the high performance of the new pulse sequence.
在本文中，我们介绍了一种脉冲序列，它能够监测由缩放偶极哈密顿量产生的相关自旋态的多量子相干分布。该脉冲序列是我们之前带有相位增量的比例重聚焦洛施密特回波（PRL回波）的一种改进，以验证加权相干量子动力学的准确性。实验采用不同的缩放因子进行，以分析总磁化强度的演化、多量子相干阶数的时间依赖性以及相关自旋簇的发展。在所有情况下，均观察到演化速率与加权因子之间存在强烈依赖性。值得注意的是，当以自时间（一种将缩放因子纳入演化时间的新时间尺度）为横坐标绘制时，所有曲线都呈现出单一趋势的重叠。换句话说，自旋系统始终表现出相同的量子演化，随着缩放因子减小而变慢，这证实了新脉冲序列的高性能。
