Valencia, S.; Calderón, M.J.; López-Mir, L.; Konstantinovic, Z.; Schierle, E.; Weschke, E.; Brey, L.; Martínez, B.; Balcells, Ll.: Enhancement of spin-orbit coupling at manganite surfaces. Physical Review B 98 (2018), p. 115142/1-8
10.1103/PhysRevB.98.115142
Open Access Version
Abstract:
Spin-orbit coupling in magnetic systems lacking inversion symmetry can give rise to nontrivial spin textures. Magnetic thin films and heterostructures are potential candidates for the formation of skyrmions and other noncollinear spin configurations as inversion symmetry is inherently lost at their surfaces and interfaces. However, manganites, in spite of their extraordinarily rich magnetic phase diagram, have not yet been considered of interest within this context as their spin-orbit coupling is assumed to be negligible. We demonstrate here, by means of angular dependent x-ray linear dichroism experiments and theoretical calculations, the existence of a noncollinear antiferromagnetic ordering at the surface of ferromagnetic La2/3Sr1/3MnO3 thin films whose properties can only be explained by an unexpectedly large enhancement of the spin-orbit interaction. Our results reveal that spin-orbit coupling, usually assumed to be very small in manganites, can be significantly enhanced at surfaces and interfaces adding a new twist to the possible magnetic orders that can arise in electronically reconstructed systems.