Dynamic magnetic phase transition induced by parametric magnon pumping
Abstract
Uncovering pathways to optically drive magnetic order-disorder transitions on ultrashort timescales can lead to the realization of novel out-of-equilibrium quantum phenomena. A long-sought pathway is to directly excite a highly non-thermal energy-momentum distribution of magnons, bypassing both charge and lattice degrees of freedom. However, this remains elusive owing to the weak coupling and large momentum mismatch between photons and magnons. Here we demonstrate strong parametric excitation of magnons across the entire Brillouin zone of the antiferromagnetic insulator SrCuOCl by periodically modulating the superexchange interaction with the electric field of light. The excitation efficiency is greatly enhanced by tuning to the van Hove singularity in the magnon spectrum, sufficient to transiently collapse the antiferromagnetic state using a pulsed laser field of 10 V/m. The order parameter recovery timescale increases by over 1000 times as a function of excitation density, reflecting a crossover from high- to low-energy magnon dominated decay dynamics. This electric-field induced parametric magnon pumping mechanism is applicable to a broad range of magnetic insulators and opens up the possibility of dynamically engineering magnon distributions by design.
Cite
@article{arxiv.2402.09521,
title = {Dynamic magnetic phase transition induced by parametric magnon pumping},
author = {Jun-Yi Shan and Jonathan B. Curtis and Mingyao Guo and Chang Jae Roh and C. R. Rotundu and Young S. Lee and Prineha Narang and Tae Won Noh and Eugene Demler and D. Hsieh},
journal= {arXiv preprint arXiv:2402.09521},
year = {2024}
}
Comments
The submitter did not obtain approval from all authors to post this paper. Jun-Yi Shan does not approve of posting this paper