Engineered lattices in condensed matter physics, such as cold atom opticallattices or photonic crystals, can have fundamentally different properties fromnaturally-occurring electronic crystals. Here, we report a novel type ofartificial quantum matter lattice. Our lattice is a multilayer heterostructurebuilt from alternating thin films of topological and trivial insulators. Eachinterface within the heterostructure hosts a set of topologically-protectedinterface states, and by making the layers sufficiently thin, we demonstratefor the first time a hybridization of interface states across layers. In thisway, our heterostructure forms an emergent atomic chain, where the interfacesact as lattice sites and the interface states act as atomic orbitals, as seenfrom our measurements by angle-resolved photoemission spectroscopy (ARPES). Bychanging the composition of the heterostructure, we can directly controlhopping between lattice sites. We realize a topological and a trivial phase inour superlattice band structure. We argue that the superlattice may becharacterized in a significant way by a one-dimensional topological invariant,closely related to the invariant of the Su-Schrieffer-Heeger model. Ourtopological insulator heterostructure demonstrates a novel experimentalplatform where we can engineer band structures by directly controlling howelectrons hop between lattice sites.
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