磁性半金属Co3Sn2S2中声子的固有圆二色性

IF 8.1 1区物理与天体物理 Q1 PHYSICS, MULTIDISCIPLINARY

Physical review letters Pub Date : 2025-05-16 DOI:10.1103/physrevlett.134.196905

R. Yang, Y.-Y. Zhu, M. Steigleder, Y.-C. Liu, C.-C. Liu, X.-G. Qiu, Tiantian Zhang, M. Dressel

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引用次数: 0

摘要

利用光谱学方法研究了铁磁Weyl半金属Co3Sn2S2中的红外有源声子。在居里温度（TC≈175 K）以下，我们观察到光学电导率中声子峰的不对称范诺线形状，反映了电子-声子耦合的存在。此外，通过极性克尔旋转和椭圆度光谱检测到的声子信号表明声子具有圆二色性。我们将声子的CD归因于它们与两个圆极化通道中倾斜的Weyl节点环上的电荷激励的独特耦合。我们的研究结果提供了实验证据，证明在没有外场的情况下，声子也可以通过与电子拓扑的耦合而变得圆极化。由于磁交换分裂逐渐改变了Co3Sn2S2中的拓扑带，声子的CD表现出明显的温度依赖性，暗示了一种有前途的操作方法。2025年由美国物理学会出版

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Inherent Circular Dichroism of Phonons in Magnetic Weyl Semimetal Co3Sn2S2

We investigated the infrared-active phonons in ferromagnetic Weyl semimetal Co3Sn2S2 using optical spectroscopy. Below the Curie temperature (TC≈175 K), we observed asymmetric Fano line shapes of phonons peaks in the optical conductivities, reflecting the presence of electron-phonon coupling. Additionally, the detected phonon signals by the polar Kerr rotation and the ellipticity spectroscopy indicate the circular dichroism (CD) of phonons. We attribute the CD of phonons to their distinct couplings with charge excitations on the tilted Weyl nodal rings in two circularly polarized channels. Our findings provide experimental evidence that, without external fields, phonons can also become circularly polarized by coupling with the electronic topology. Since the magnetic exchange splitting gradually shifts the topological bands in Co3Sn2S2, the CD of phonons exhibits significant temperature dependence, hinting at a promising approach for manipulation.

Published by the American Physical Society

2025

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来源期刊

Physical review letters 物理-物理：综合

CiteScore

16.50

自引率

7.00%

发文量

2673

审稿时长

2.2 months

期刊介绍： Physical review letters(PRL)covers the full range of applied, fundamental, and interdisciplinary physics research topics: General physics, including statistical and quantum mechanics and quantum information Gravitation, astrophysics, and cosmology Elementary particles and fields Nuclear physics Atomic, molecular, and optical physics Nonlinear dynamics, fluid dynamics, and classical optics Plasma and beam physics Condensed matter and materials physics Polymers, soft matter, biological, climate and interdisciplinary physics, including networks