We use time-resolved hard x-ray diffraction to investigate the structural dynamics of the multiferroic insulator TbMnO3 in the low temperature antiferromagnetic and ferroelectrically ordered phase. The lattice response following photoexcitation at 1.55 eV is detected by measuring the (0 2 4) and (1 3 -5) Bragg reflections. A 0.02% tensile strain, normal to the surface, is seen to arise within 20 - 30 ps. The magnitude of this transient strain is over an order of magnitude lower than that predicted from laser-induced heating, which we attribute to a bottleneck in the energy transfer between the electronic and lattice subsystems. The timescale for the transient expansion is consistent with that of previously reported demagnetization dynamics. We discuss a possible relationship between structural and demagnetization dynamics in TbMnO3, in which photoinduced atomic motion modulates the exchange interaction, leading to a destruction of the magnetic order in the system.
@article{arxiv.2201.10009,
title = {Photoinduced structural dynamics of multiferroic TbMnO$_3$},
author = {Elsa Abreu and Matteo Savoini and Larissa Boie and Paul Beaud and Vincent Esposito and Martin Kubli and Martin J. Neugebauer and Michael Porer and Urs Staub and Bulat Burganov and Chris Dornes and Angel Rodriguez-Fernandez and Lucas Huber and Gabriel Lantz and José R. L. Mardegan and Sergii Parchenko and Jochen Rittmann and Cris Svetina and Gerhard Ingold and Steven L. Johnson},
journal= {arXiv preprint arXiv:2201.10009},
year = {2024}
}