Novel Quantum Heterostructures enabled by Membrane Epitaxy

Engineering of sharp interfaces and heterostructures with thin films of quantum materials is a cornerstone of thin films epitaxy. However, there is an inherent constraint of lattice compatibility, concerning not only the lattice symmetry but also lattice size, limiting the realizability of epitaxially grown heterostructures. To solve this problem and overcome that constraint, we introduce "vector substrates", for which the template layer for epitaxy can be chosen independently of the bulk of the substrate. The fabrication of vector substrates leverages thin-film membrane technology. The process begins by growing a template layer on a parent substrate. The template layer is then transferred onto a carrier substrate, thereby generating the vector substrate. Furthermore, these vector substrates can be handled and utilized for growth in the same way a traditional substrate is used. We show that this approach allows the deposition of heterostructures of quantum materials with clean and novel interfaces, opening up an unprecedented variety of possibilities in quantum materials research.<br/><br/><b>References:</b><br/>V. Harbola et al., Vector Substrates: Idea, Design, and Realization, Adv. Func. Mater. (In press) Article DOI: 10.1002/adfm.202306289 (2023).