Xu Xitong, Yin Jia-Xin, Ma Wenlong, Tien Hung-Ju, Qiang Xiao-Bin, Reddy P V Sreenivasa, Zhou Huibin, Shen Jie, Lu Hai-Zhou, Chang Tay-Rong, Qu Zhe, Jia Shuang
Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, 230031, China.
International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
Nat Commun. 2022 Mar 7;13(1):1197. doi: 10.1038/s41467-022-28796-6.
In ordinary materials, electrons conduct both electricity and heat, where their charge-entropy relations observe the Mott formula and the Wiedemann-Franz law. In topological quantum materials, the transverse motion of relativistic electrons can be strongly affected by the quantum field arising around the topological fermions, where a simple model description of their charge-entropy relations remains elusive. Here we report the topological charge-entropy scaling in the kagome Chern magnet TbMnSn, featuring pristine Mn kagome lattices with strong out-of-plane magnetization. Through both electric and thermoelectric transports, we observe quantum oscillations with a nontrivial Berry phase, a large Fermi velocity and two-dimensionality, supporting the existence of Dirac fermions in the magnetic kagome lattice. This quantum magnet further exhibits large anomalous Hall, anomalous Nernst, and anomalous thermal Hall effects, all of which persist to above room temperature. Remarkably, we show that the charge-entropy scaling relations of these anomalous transverse transports can be ubiquitously described by the Berry curvature field effects in a Chern-gapped Dirac model. Our work points to a model kagome Chern magnet for the proof-of-principle elaboration of the topological charge-entropy scaling.
在普通材料中,电子传导电流和热量,其电荷 - 熵关系遵循莫特公式和维德曼 - 弗兰兹定律。在拓扑量子材料中,相对论电子的横向运动可能会受到拓扑费米子周围产生的量子场的强烈影响,其电荷 - 熵关系的简单模型描述仍然难以捉摸。在此,我们报告了在 Kagome 陈磁体 TbMnSn 中的拓扑电荷 - 熵标度,其具有原始的 Mn Kagome 晶格且具有很强的面外磁化。通过电输运和热输运,我们观察到具有非平凡贝里相位、大费米速度和二维性的量子振荡,支持了磁性 Kagome 晶格中狄拉克费米子的存在。这种量子磁体还表现出大的反常霍尔、反常能斯特和反常热霍尔效应,所有这些效应在高于室温时仍然存在。值得注意的是,我们表明这些反常横向输运的电荷 - 熵标度关系可以在陈能隙狄拉克模型中由贝里曲率场效应普遍描述。我们的工作指出了一个模型 Kagome 陈磁体,用于拓扑电荷 - 熵标度的原理验证阐述。