Nature Physics, Published online: 20 April 2026; doi:10.1038/s41567-026-03231-5
Charge-transfer excitations, which define the optical bandgap in many insulators, also contribute to magnetic exchange in antiferromagnets. Femtosecond optical pumping of these transitions in canted antiferromagnet DyFeO3 reshapes the spin-wave spectrum — the set of collective spin excitations that define the dynamics of the antiferromagnet — without destroying the long-range order.
