Department of Physics, Astronomy & Geosciences Fall ’24 Seminar Series
Event Information: Physics, Astronomy & Geosciences Fall ’24 Seminar Series: Exciton-activated phonon magnetic in monolayer MoS2 – Towson University
Fri., Oct. 11, 2024
11am – 11:50am
Science Complex, Room 1230
Speaker: Dr. Wencan Jin, Assistant Professor of Physics & Adjunct Professor of Electrical and Computer Engineering, Auburn University
Title: Exciton-activated phonon magnetic moment in monolayer MoS2
Abstract: Optical excitation of chiral phonons plays a vital role in studying the phonon-driven magnetic phenomena in solids. Transition metal dichalcogenides host chiral phonons at high symmetry points of the Brillouin zone, providing an ideal platform to explore the interplay between chiral phonons and valley degree of freedom. In this talk, I will present helicity-resolved magneto-Raman studies of monolayer MoS2, in which a doubly degenerate chiral phonon mode is found at ∼270cm−1. Our wavelength- and temperature-dependent measurements show that this chiral phonon is activated through the resonant excitation of A exciton. Under an out-of-plane magnetic field, the chiral phonon exhibits giant Zeeman splitting, which corresponds to an effective magnetic moment of ∼2.5μB. Our study provides important insights into lifting the chiral phonon degeneracy in an achiral covalent material, paving a route to excite and control chiral phonons.
Reference: Chunli Tang et al., Phys. Rev. B 109, 155426 (2024)
https://doi.org/10.1103/PhysRevB.109.155426
Categorised in: General
This post was written by Charles, Amanda G.