Mohamed Nawwar: Magnon Phonon Hybridization as a Driver for Topology in MnPS3

Date: Thursday, November 6th, 2025

Location: Elings Hall, room 1601

Time: 12:30 pm - 1:30 pm

Magnon Phonon Hybridization as a Driver for Topology in MnPS3

Abstract: Recent studies have demonstrated that the thermal Hall effect can originate from magnons (magnon Hall effect), phonons (phonon Hall effect), or their combination (magnon-polaron Hall effect). The magnon-polaron Hall effect, first observed in 2017 in Fe2Mo3O8, held the record for the strongest thermal Hall signal in an insulating magnet at the time. In this study, we explore the thermal Hall effect in MnPS3, an insulating antiferromagnetic material exhibiting a spin-flop transition and strong magnetoelastic coupling, making it a strong candidate for studying the magnon-polaron Hall effect. We report a record-high thermal Hall angle down to 4 K, and show that it cannot be accounted for by standard calculations based on the intrinsic magnon-polaron Berry curvature. Our findings provide an in-depth analysis of the role of the spin-flop transition in the thermal properties of MnPS3 and call for further investigations of magnon-phonon interactions and their influence on the Berry curvature.

Bio: Mohamed Nawwar is a Ph.D. candidate in Materials Science and Engineering at The Ohio State University, advised by Prof. Joseph Heremans. His research explores the interplay between electrons, phonons, and magnons in quantum and topological materials through high-precision thermal and thermoelectric transport measurements. His work aims to uncover how topology and quasiparticle coupling influence transport and how these effects can be harnessed in devices. Beyond his research, Mohamed is one of the founding members of the Conference Across MRSEC and PREM Schools (CAMPS), a student-led initiative to create a collaborative space for all students and faculty at all MRSEC and PREM institutions.