Spin excitations and spin wave gap in the ferromagnetic Weyl semimetal Co3Sn2S2

被引：40

作者：

Liu, Chang ^{[1
,2
]}

Shen, JianLei ^{[1
,2
]}

Gao, JiaCheng ^{[1
,2
]}

Yi, ChangJiang ^{[1
,2
]}

Liu, Di ^{[1
,2
]}

Xie, Tao ^{[1
,2
]}

Yang, Lin ^{[1
,2
]}

Danilkin, Sergey ^{[3
]}

Deng, GuoChu ^{[3
]}

Wang, WenHong ^{[1
,4
]}

Li, ShiLiang ^{[1
,2
,4
]}

Shi, YouGuo ^{[1
,2
,4
,5
]}

Weng, HongMing ^{[1
,2
,4
,5
]}

Liu, EnKe ^{[1
,4
]}

Luo, HuiQian ^{[1
,4
]}

机构：

[1] Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China

[2] Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100190, Peoples R China

[3] Australian Nucl Sci & Technol Org, Australian Ctr Neutron Scattering, Lucas Heights, NSW 2234, Australia

[4] Songshan Lake Mat Lab, Dongguan 523808, Peoples R China

[5] Huairou Natl Comprehens Sci Ctr, Phys Sci Lab, Beijing 101407, Peoples R China

来源：

SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY | 2021年 / 64卷 / 01期

基金：

北京市自然科学基金; 中国国家自然科学基金;

关键词：

magnetic Weyl semimetal; topological materials; spin excitations; neutron scattering; HALF-ANTIPEROVSKITES; DIRAC FERMIONS; PHASE;

D O I：

10.1007/s11433-020-1597-6

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We report a comprehensive neutron scattering study on the spin excitations in the magnetic Weyl semimetal Co3Sn2S2 with a quasi-two-dimensional structure. Both in-plane and out-of-plane dispersions of the spin waves were revealed in the ferromagnetic state. Similarly, dispersive but damped spin excitations were found in the paramagnetic state. The effective exchange interactions were estimated using a semi-classical Heisenberg model to consistently reproduce the experimental T-C and spin stiffness. However, a full spin wave gap below E-g= 2.3 meV was observed at T= 4 K. This value was considerably larger than the estimated magnetic anisotropy energy (similar to 0.6 meV), and its temperature dependence indicated a significant contribution from the Weyl fermions. These results suggest that Co3Sn2S2 is a three-dimensional correlated system with a large spin stiffness, and the low-energy spin dynamics can interplay with the topological electron states.

引用

页数：7

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