Dissecting spin-phonon equilibration in ferrimagnetic insulators by ultrafast lattice excitation.

ABSTRACT: To gain control over magnetic order on ultrafast time scales, a fundamental understanding of the way electron spins interact with the surrounding crystal lattice is required. However, measurement and analysis even of basic collective processes such as spin-phonon equilibration have remained challenging. Here, we directly probe the flow of energy and angular momentum in the model insulating ferrimagnet yttrium iron garnet. After ultrafast resonant lattice excitation, we observe that magnetic order reduces on distinct time scales of 1 ps and 100 ns. Temperature-dependent measurements, a spin-coupling analysis, and simulations show that the two dynamics directly reflect two stages of spin-lattice equilibration. On the 1-ps scale, spins and phonons reach quasi-equilibrium in terms of energy th

SUBMITTER: Maehrlein SF 

PROVIDER: S-EPMC6044736 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature