Nonlinear phononics as a universal mechanism for ultrafast switching of spins

Andrei Kirilyuk

Here I will show how an ultrafast resonant excitation of optical phonon modes can switch magnetic order. The mechanism appears to be very universal, and is shown to work in samples with very different magnetic order, including weak ferromagnets and antiferromagnets. Using single-shot time resolved microscopy, we demonstrate that the dynamics of switching proceeds via a strongly inhomogeneous state, related to the spin-wave instabilities that appear due to large amplitude of precessional motion.