...
首页> 外文期刊>Physical review >Angle-resolved NMR: Quantitative theory of ~(75)As T_1 relaxation rate in BaFe_2As_2
【24h】

Angle-resolved NMR: Quantitative theory of ~(75)As T_1 relaxation rate in BaFe_2As_2

机译:角分辨NMR:BaFe_2As_2中〜(75)As T_1弛豫率的定量理论

获取原文
获取原文并翻译 | 示例
           

摘要

While NMR measurements of nuclear energy spectra are routinely used to characterize the static properties of quantum magnets, the dynamical information locked in NMR 1/ T_1 relaxation rates remains notoriously difficult to interpret. The difficulty arises from the fact that information about all possible low-energy spin excitations of the electrons, and their coupling to the nuclear moments, is folded into a single number l/T_1. Here, we develop a quantitative theory of the NMR 1/T_1 relaxation rate in a collinear antiferromagnet, focusing on the specific example of BaFe_2As_2. One of the most striking features of magnetism in BaFe_2As_2 is a strong dependence of 1/T_1 on the orientation of the applied magnetic field. By careful analysis of the coupling between the nuclear and electronic moments, we show how this anisotropy arises from the "filtering" of spin fluctuations by the form factor for transferred hyperfine interactions. This allows us to make convincing, quantitative fits to experimental 1/T_1 data for BaFe_2As_2 for different field orientations. We go on to show how a quantitative, angle-dependent theory for the relaxation rate leads to new ways of measuring the dynamical parameters of magnetic systems, in particular, the spin-wave velocities.
机译:虽然通常使用核能谱的NMR测量来表征量子磁体的静态特性,但是众所周知,锁定在NMR 1 / T_1弛豫率中的动力学信息仍然难以解释。困难来自于以下事实:关于电子的所有可能的低能自旋激发及其与核矩的耦合的信息被折叠为一个整数L / T_1。在此,我们重点研究了BaFe_2As_2的具体例子,从而得出了共线反铁磁体中NMR 1 / T_1弛豫率的定量理论。 BaFe_2As_2中磁性的最显着特征之一是1 / T_1对所施加磁场的方向的强烈依赖性。通过仔细分析核矩和电子矩之间的耦合,我们显示出这种各向异性是如何通过自旋涨落的“过滤”被传递的超精细相互作用的形状因数产生的。这使我们能够针对不同场取向的BaFe_2As_2对实验1 / T_1数据进行令人信服的定量拟合。我们继续展示了弛豫速率的一种定量的,与角度相关的理论如何导致测量磁系统动力学参数(特别是自旋波速度)的新方法。

著录项

  • 来源
    《Physical review》 |2011年第18期|p.184437.1-184437.17|共17页
  • 作者

    Andrew Smerald; Nic Shannon;

  • 作者单位

    H. H. Wills Physics Laboratory, University of Bristol, Tyndall Av, BS8-1TL Bristol, United Kingdom;

    H. H. Wills Physics Laboratory, University of Bristol, Tyndall Av, BS8-1TL Bristol, United Kingdom;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    relaxation effects;

    机译:松弛效应;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号