Debnath Kamanasish, Dold Gavin, Morton John J L, Mølmer Klaus
Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom.
Phys Rev Lett. 2020 Sep 25;125(13):137702. doi: 10.1103/PhysRevLett.125.137702.
We show experimentally and describe theoretically how a conventional magnetic resonance Hahn echo sequence can lead to a self-stimulated pulse echo train when an inhomogeneously broadened spin ensemble is coupled to a resonator. Effective strong coupling between the subsystems assures that the first Hahn echo can act as a refocusing pulse on the spins, leading to self-stimulated secondary echoes. Within the framework of mean field theory, we show that this process can continue multiple times leading to a train of echoes. We introduce an analytical model that explains the shape of the first echo and numerical results that account well for the experimentally observed shape and strength of the echo train and provides insights into the collective effects involved.
我们通过实验展示并从理论上描述了，当非均匀展宽的自旋系综与谐振器耦合时，传统的磁共振哈恩回波序列如何导致自激脉冲回波序列。子系统之间有效的强耦合确保了第一个哈恩回波可以作为自旋上的重聚焦脉冲，从而导致自激二次回波。在平均场理论的框架内，我们表明这个过程可以多次持续，导致一系列回波。我们引入了一个解析模型来解释第一个回波的形状，并给出了数值结果，这些结果很好地解释了实验中观察到的回波序列的形状和强度，并深入了解了其中涉及的集体效应。
