Dynamic magnetic phase transition induced by parametric magnon pumping
Creators
-
1.
California Institute of Technology
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 nonthermal 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 Sr₂Cu₃O₄Cl₂ 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 10⁹ 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.
Copyright and License
© 2024 American Physical Society.
Acknowledgement
Files
PhysRevB.109.054302.pdf
Files
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Additional details
Identifiers
- ISSN
- 2469-9969
Related works
- Is supplemented by
- https://journals.aps.org/prb/supplemental/10.1103/PhysRevB.109.054302/SI_PRB_v3.pdf (URL)
Funding
- United States Army Research Office
- W911NF-16-1-0361
- National Science Foundation
- PHY-1733907
- Swiss National Science Foundation
- 200021_212899
- Institute for Basic Science
- IBS-R009-D1
- United States Department of Energy
- DE-SC0022277
- Gordon and Betty Moore Foundation
- GBMF8048
- John Simon Guggenheim Memorial Foundation
- United States Department of Energy
- DE-AC02-76SF00515