Magnetic excitons in a suspended 2D antiferromagnetic membrane

TL;DR

This study investigates magnetic excitons in a suspended 2D antiferromagnetic NiPS3 membrane, revealing magnon-mediated optical transitions, strain tuning effects, and localized exciton behavior linked to zigzag magnetic order.

Contribution

It uncovers the nature of magnetic excitons in a 2D antiferromagnetic membrane and demonstrates magnon-mediated optical transitions and strain tuning effects.

Findings

Identification of nematic zigzag magnetic states

Observation of magnon-dressed excitons

Strain-dependent tuning of emission lines

Abstract

Layered magnetic and strongly correlated materials present a rich platform for condensed matter physics with intrinsic properties intertwined by magnetism and low-dimensionality. A suspended light-emitting 2D antiferromagnetic membrane forms a highly controllable hybrid system in which the interplay between spin ordering, optical and mechanical degrees of freedom can be uniquely explored. NiPS$_3$ hosts excitons responsible for a puzzling luminescence down to a few atomic layers, linked to its zigzag antiferromagnetic order. The nature of these excitons remains unclear. Here we report on the magnetic excitons of a suspended few-layer NiPS$_3$ membrane. We reveal nematic zigzag states and study the optical transitions induced by the magnon-mediated motion of the excitation in the magnetic lattice, resulting in magnon-dressed excitons. We observe a strain tuning of these emission lines, dependent on their microscopic origin, with rates that sign a strong localization of the magnetic excitons, fading with the number of magnon-mediated hops.