Cryogenic Research Center, University of Tokyo, Tokyo, Japan.
Phys Rev Lett. 2007 Aug 24;99(8):086602. doi: 10.1103/PhysRevLett.99.086602.
The anomalous Hall effect (AHE) and anomalous Nernst effect (ANE) are experimentally investigated in a variety of ferromagnetic metals including pure transition metals, oxides, and chalcogenides, whose resistivities range over 5 orders of magnitude. For these ferromagnets, the transverse conductivity sigma{xy} versus the longitudinal conductivity sigma{xx} shows a crossover behavior with three distinct regimes in accordance qualitatively with a recent unified theory of the intrinsic and extrinsic AHE. We also found that the transverse Peltier coefficient alpha{xy} for the ANE obeys the Mott rule. These results offer a coherent and semiquantitative understanding of the AHE and ANE to an issue of controversy for many decades.
实验研究了多种铁磁金属中的反常霍尔效应(AHE)和反常能斯特效应(ANE),包括纯过渡金属、氧化物和硫族化物,它们的电阻率跨越了 5 个数量级。对于这些铁磁体,横向电导率 sigma{xy}与纵向电导率 sigma{xx}的比值表现出交叉行为,与最近提出的内在和外在 AHE 的统一理论定性一致。我们还发现,ANE 的横向佩尔捷系数 alpha{xy}符合莫特定律。这些结果为 AHE 和 ANE 提供了一个连贯的、半定量的理解,解决了几十年来存在争议的问题。