Static strain in complex oxide heterostructures has been extensively used to engineer electronic and magnetic properties at equilibrium. In the same spirit, deformations of the crystal lattice with light may be used to achieve functional control across hetero-interfaces dynamically. Here, by exciting large amplitude infrared-active vibrations in a LaAlO3 substrate we induce magnetic order melting in a NdNiO3 film across a hetero-interface. Femtosecond Resonant Soft X-ray Diffraction is used to determine the spatial and temporal evolution of the magnetic disordering. We observe a magnetic melt front that grows from the substrate interface into the film, at a speed that suggests electronically driven propagation. Light control and ultrafast phase front propagation at hetero-interfaces may lead to new opportunities in optomagnetism, for example by driving domain wall motion to transport information across suitably designed devices.
@article{arxiv.1505.00601,
title = {Spatially resolved ultrafast magnetic dynamics launched at a complex-oxide hetero-interface},
author = {M. Först and A. D. Caviglia and R. Scherwitzl and R. Mankowsky and P. Zubko and V. Khanna and H. Bromberger and S. B. Wilkins and Y. -D. Chuang and W. S. Lee and W. F. Schlotter and J. J. Turner and G. L. Dakovski and M. P. Minitti and J. Robinson and S. R. Clark and D. Jaksch and J. -M. Triscone and J. P. Hill and S. S. Dhesi and A. Cavalleri},
journal= {arXiv preprint arXiv:1505.00601},
year = {2015}
}