高阶多量子跃迁的一维直接检测──Raman磁共振方法

ONE-DIMENSIONAL DETECTION OF HIGHER-ORDER MULTIPLE QUANTUM TRANSITIONS BY RAMAN MAGNETIC RESONANCE

研究了异核AX3自旋体系的初始态为最高阶量子相干态时的Raman磁共振谱．研究表明，唯有制备高阶多量子相干的初始态时才有可能对高阶多量子跃迁进行有效检测．积算符理论的精确性使得理论上准确地预言了Raman磁共振谱中各阶多量子跃迁频率、谱线强度，使得各阶多量子跃迁频率相互交错时仍有可能解析谱图．在Raman磁共振实验中采用了正负频偏交替变化采样的方法，对单量子信号进行压制。

Raman Magnetic Resonance (RMR) spectroscopy for a heteronuclear AX3 spin system isrecorded by perturbing the highest-order quantum coherence state. The RMR experimentshows that an effective way for detecting higher-order quantum transitions is to prepare thehigher-order multiple quantum (MQ) coherence in the initial state. The product operatorformalism provides an exact method to predict arbitrary order MQ frequencies and intensitiesof RMR spectroscopy. By means of accumulation of Positive-negative alternate offset, thestrong single quantum signals are suppressed and hence the MQ transition signals can be detected with a higher efficiency.