A Molecular Approach for Engineering Interfacial Interactions in Magnetic-Topological Insulator Heterostructures
Abstract
Controlling interfacial interactions in magnetic/topological insulator heterostructures is a major challenge for the emergence of novel spin-dependent electronic phenomena. As for any rational design of heterostructures that rely on proximity effects, one should ideally retain the overall properties of each component while tuning interactions at the interface. However, in most inorganic interfaces interactions are too strong, consequently perturbing, and even quenching, both the magnetic moment and the topological surface states at each side of the interface. Here we show that these properties can be preserved by using ligand chemistry to tune the interaction of magnetic ions with the surface states. By depositing Co-based porphyrin and phthalocyanine monolayers on the surface of BiTe thin films, robust interfaces are formed that preserve undoped topological surface states as well as the pristine magnetic moment of the divalent Co ions. The selected ligands allow us to tune the interfacial hybridization within this weak interaction regime. These results, which are in stark contrast with the observed suppression of the surface state at the first quintuple layer of BiSe induced by the interaction with Co phthalocyanines, demonstrate the capability of planar metal-organic molecules to span interactions from the strong to the weak limit.
Cite
@article{arxiv.2004.14219,
title = {A Molecular Approach for Engineering Interfacial Interactions in Magnetic-Topological Insulator Heterostructures},
author = {Marc G. Cuxart and Miguel Angel Valbuena and Roberto Robles and César Moreno and Frédéric Bonell and Guillaume Sauthier and Inhar Imaz and Heng Xu and Corneliu Nistor and Alessandro Barla and Pierluigi Gargiani and Manuel Valvidares and Daniel Maspoch and Pietro Gambardella and Sergio O. Valenzuela and Aitor Mugarza},
journal= {arXiv preprint arXiv:2004.14219},
year = {2020}
}