School of Chemistry, University of Southampton, SO17 1BJ Southampton, United Kingdom.
J Chem Phys. 2023 Mar 28;158(12):124204. doi: 10.1063/5.0138146.
The Aharonov-Anandan phase is a contribution to the phase acquired by the cyclic evolution of a quantum state, which depends only on the geometric properties of its trajectory. We report the study and the exploitation of the Aharonov-Anandan phase by nuclear magnetic resonance interferometry techniques in homonuclear spin-1/2 pairs in the near-equivalence limit. We introduce a new method for engineering effective zero-quantum Hamiltonians with an arbitrary phase in the transverse plane. We use this method to generate a variety of cyclic zero-quantum paths, enabling direct study of the geometric Aharonov-Anandan phase to probe the rotational characteristics of the zero-quantum subspace. We show that the geometric Aharonov-Anandan phase may be used for efficient double-quantum excitation in strongly coupled spin pairs. We find that geometric double-quantum excitation outperforms the standard method by a factor of 2 in experiments performed on a typical case involving near-equivalent spin pairs.
阿哈罗诺夫-安丹诺相位是量子态循环演化所获得的相位的贡献，仅取决于其轨迹的几何性质。我们报告了在近等效极限下同核自旋-1/2 对中通过核磁共振干涉技术对阿哈罗诺夫-安丹诺相位的研究和利用。我们引入了一种新的方法，用于在横向平面中工程具有任意相位的有效零量子哈密顿量。我们使用该方法生成各种循环零量子路径，能够直接研究几何阿哈罗诺夫-安丹诺相位，以探测零量子子空间的旋转特性。我们表明，几何阿哈罗诺夫-安丹诺相位可用于在强耦合自旋对中进行高效的双量子激发。我们发现，在对涉及近等效自旋对的典型情况进行的实验中，几何双量子激发的效率比标准方法高 2 倍。
