Indium Epitaxy on SiC(0001): A Roadmap to Large Scale Growth of the Quantum Spin Hall Insulator Indenene

Indenene-the triangular single layer phase of indium-is a novel large gap (similar to 120 meV) quantum spin Hall (QSH) insulator that stabilizes on SiC(0001) substrates. Thanks to excellent lattice matching, indenene nucleates in monodomains that are promising for devices if synthesized in the micrometer range. Here, we establish a simple, but robust and scalable indenene fabrication protocol based on an initial Stranski-Krastanov growth stage followed by a short anneal whose temperature selects between a three, two, or one monolayer In coverage. Their specific structural and electronic properties produce distinct fingerprints in experimental surface characterization by electron microscopy, diffraction, and spectroscopy, thus providing an efficient metric for the synthesis of large scale high-quality indenene on SiC.