State Key Lab of Superhard Materials, Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
Department of Physics, Tohoku University, Sendai, Miyagi 980-8578, Japan.
Nat Commun. 2017 Apr 20;8:15084. doi: 10.1038/ncomms15084.
Resistively detected NMR (RDNMR) based on dynamic nuclear polarization (DNP) in a quantum Hall ferromagnet (QHF) is a highly sensitive method for the discovery of fascinating quantum Hall phases; however, the mechanism of this DNP and, in particular, the role of quantum Hall edge states in it are unclear. Here we demonstrate the important but previously unrecognized effect of chiral edge modes on the nuclear spin polarization. A side-by-side comparison of the RDNMR signals from Hall bar and Corbino disk configurations allows us to distinguish the contributions of bulk and edge states to DNP in QHF. The unidirectional current flow along chiral edge states makes the polarization robust to thermal fluctuations at high temperatures and makes it possible to observe a reciprocity principle of the RDNMR response. These findings help us better understand complex NMR responses in QHF, which has important implications for the development of RDNMR techniques.
基于量子霍尔铁磁体（QHF）中动态核极化（DNP）的电阻检测 NMR（RDNMR）是发现迷人量子霍尔相的高灵敏度方法；然而，这种 DNP 的机制，特别是量子霍尔边缘态在其中的作用尚不清楚。在这里，我们展示了手性边缘模式对核自旋极化的重要但以前未被认识到的影响。霍尔条和科宾诺磁盘配置的 RDNMR 信号的并排比较使我们能够区分 QHF 中体相和边缘态对 DNP 的贡献。沿着手性边缘态的单向电流流动使得极化对高温下的热波动具有鲁棒性，并使得观察 RDNMR 响应的互易原理成为可能。这些发现有助于我们更好地理解 QHF 中复杂的 NMR 响应，这对 RDNMR 技术的发展具有重要意义。
Zotero 插件
