Magnetic anisotropy and electronic structure of molecular networks on topological insulators

Resumen del póster presentado al 1st Workshop Spain-Taiwan: "2D Materials and Interfaces for Spintronics", celebrado en Barcelona (España) del 23 al 25 de octubre de 2017.In topological insulators (TIs), long-range interactions between magnetic dopants mediated by the topological surface states can give rise to exotic phenomena such as the quantum anomalous Hall effect (QAHE) and dissipationless spin polarized edge currents. Such interactions, however, only occur under specific conditions of magnetic moment, anisotropy, and exchange coupling with the surrounding electron bath. Here we propose the use of metalorganic networks as an alternative strategy for tuning the electronic and magnetic interaction between the magnetic impurity and the substrate. The electronic and magnetic properties of TI surfaces modified by Brominated Cobalt tetraphenyl-porphyrin (4Br-CoTPP) networks are studied by combining Angle Resolved Photoemission Spectroscopy (ARPES) with X-Ray Magnetic Circular Dichroism (XMCD) measurements. ARPES measurements reveal that the topological surface state (TSS) is not quenched upon adsorption of slightly more than 1 ML 4Br-CoTPP in contrast with previous ARPES in Cobalt phthalocyanine/TI interfaces. The weaker interaction between the molecular layer and the substrate is confirmed by XMCD measurements where a strong in-plane magnetic moment is preserved. This ligand-mediated tuneability of interfacial interactions, together with the well-known capability of controlling magnetic anisotropy, makes the use of metalorganic molecules a promising route for engineering the electronic and magnetic properties of hybrid TI-based heterostructures.Peer reviewe