铁磁体SrRuO₃中电子与自旋自由度的相互作用：磁振子能隙与劲度的反常软化

Interplay of Electronic and Spin Degrees in Ferromagnetic SrRuO_{3}: Anomalous Softening of the Magnon Gap and Stiffness.

作者信息

Jenni K, Kunkemöller S, Brüning D, Lorenz T, Sidis Y, Schneidewind A, Nugroho A A, Rosch A, Khomskii D I, Braden M

机构信息

II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln, Germany.

Laboratoire Léon Brillouin, C.E.A./C.N.R.S., F-91191 Gif-sur-Yvette CEDEX, France.

出版信息

Phys Rev Lett. 2019 Jul 3;123(1):017202. doi: 10.1103/PhysRevLett.123.017202.

DOI:10.1103/PhysRevLett.123.017202

PMID:31386396

Abstract

The magnon dispersion of ferromagnetic SrRuO_{3} was studied by inelastic neutron scattering experiments on single crystals as a function of temperature. Even at low temperature the magnon modes exhibit substantial broadening pointing to strong interaction with charge carriers. We find an anomalous temperature dependence of both the magnon gap and the magnon stiffness, which soften upon cooling in the ferromagnetic phase. Both effects trace the temperature dependence of the anomalous Hall effect and can be attributed to the impact of Weyl points, which results in the same relative renormalization in the spin stiffness and magnon gap.

摘要

通过对单晶进行非弹性中子散射实验，研究了铁磁体SrRuO₃的磁振子色散随温度的变化。即使在低温下，磁振子模式也表现出明显的展宽，这表明与电荷载流子有强烈的相互作用。我们发现磁振子能隙和磁振子刚度都有反常的温度依赖性，在铁磁相中冷却时它们会变软。这两种效应都追踪了反常霍尔效应的温度依赖性，并且可以归因于外尔点的影响，这导致了自旋刚度和磁振子能隙中相同的相对重整化。