Title:Magnetic Signature of Chiral Phonons Revealed by Neutron Spectroscopy in Multiferroic Fe_2-xZn_xMo₃O₈ systems

Time：2026/4/29（星期三）10:00 AM

报告地点：中科院物理研究所M楼236会议室

报告人: 鲍嵩

工作单位：南京大学物理学院

Abstract: 

Chiral phonons, characterized by circularly polarized ionic motions that carry angular momentum and associated magnetic moments, have recently emerged as a new frontier in condensed matter physics. They are expected to enable novel phenomena such as phonon magnetism and the phonon Hall effect. While most existing studies have focused on nonmagnetic systems via optical probes, their direct detection in magnetic materials and coupling to spin excitations remain largely unexplored. In this talk, I will present direct neutron detection of chiral phonons, together with energy-momentum-resolved mapping of their magnetic signatures in multiferroic Fe_2-xZn_xMo₃O₈. First, I will show the discovery of topological magnon polarons in the parent compound, evidencing strong magnon-phonon coupling. Combined with magneto-Raman measurements, we further identify chiral phonons and uncover remarkably large phonon magnetic moments reaching the order of μ_B. Upon 12.5% Zn substitution, the system undergoes a metamagnetic transition from an antiferromagnetic to a ferrimagnetic state. The phonon spectra exhibit pronounced magnetic scattering, out-of-plane intensity modulation, intrinsic mode splitting, and field-induced Zeeman shifts---hallmarks that are absent in conventional linear phonons. Our results provide the first direct, momentum-resolved observation of chiral-phonon dispersions using neutron spectroscopy, establish their distinct magnetic scattering signatures in magnetically ordered states, and open a new avenue for probing phonon magnetism in quantum materials.

Resume:

鲍嵩，南京大学物理学院助理教授。2021年毕业于南京大学并获博士学位，师从温锦生教授，随后留校从事博士后研究，2024年获聘准聘助理教授。主要从事量子磁性材料的单晶生长与中子散射研究，在新型量子磁性态及新颖元激发的发现方面取得了若干成果。以第一/通讯（含共同）作者身份发表论文17篇，包括2篇Nat. Phys.、3篇Nat. Commun.、1篇PRX和1篇PRL，论文总引用逾千次。

邀请人：李西阳（82649247，xiyang.li@iphy.ac.cn）