April 7 - 11, 2025
Seattle, Washington
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2025 MRS Spring Meeting & Exhibit
CH02.03.03

Terahertz Control of Magno-Phononics in van der Waals Antiferromagnets

When and Where

Apr 9, 2025
9:30am - 10:00am
Summit, Level 3, Room 343

Presenter(s)

Co-Author(s)

Honglie Ning1,Nuh Gedik1

Massachusetts Institute of Technology1

Abstract

Honglie Ning1,Nuh Gedik1

Massachusetts Institute of Technology1
Coherent manipulation of magnetism via lattice provides unprecedented opportunities for controlling spintronic functionalities on the ultrafast timescale. By coherently driving magnons and phonons in the THz spectral range, a vast array of phenomena can emerge from their intricate coupling. Here, I will present two demonstrations by leveraging the strong coupling between magnons and Raman-active phonons in van der Waals antiferromagnets. First, I will discuss how this interaction facilitates both linear and quadratic excitation of magnon-polarons — magnon-phonon hybrid quasiparticles — using intense THz pulses. This approach provides an innovative method to control quasiparticle dynamical symmetry by tuning the THz field strength and polarization. The polarimetry of the resulting coherent oscillation amplitude reveals a breaking of the crystallographic C2 symmetry, driven by strong interference between the two excitation channels. Second, I will demonstrate how nondegenerate chiral phonons can be induced by coupling to chiral magnons. Such nondegeneracy enables their coherent excitation with linearly polarized terahertz pulses. By tuning the terahertz drive polarization and measuring phase-resolved polarimetry of the resulting coherent oscillations, we can determine the ellipticity and map the trajectory of these hybrid quasiparticles. Our findings outline a novel roadmap towards phonon-controlled spintronic functionalities and unlock a wide range of possibilities to manipulate material properties, ranging from generation of metastable magnetic states via displacive phonon excitation to the modulation of exchange interactions by phonon-Floquet engineering.

Keywords

optical properties | quantum materials

Symposium Organizers

Tze Chien Sum, Nanyang Technological University
Yuanyuan Zhou, Hong Kong University of Science and Technology
Burak Guzelturk, Argonne National Laboratory
Mengxia Liu, Yale University

Symposium Support

Bronze
Ultrafast Systems LLC

Session Chairs

Peijun Guo
Mengxia Liu

In this Session