Atomically precise mechanosynthesis of carbon structures on hydrogenated Si(100) by inverted-mode STM

Authors:Megan Cowie, Chris Deimert, Ryan Groome, Alex Inayeh, Robert J. Kirby, Cameron J. Mackie, Jonathan Myall, Sam Rohe, Luis Sandoval, Khalil Sayed-Akhmad, Bheeshmon Thanabalasingam, Reid Wotton, Rafik Addou, Aly Asani, Brandon Blue, Adam Bottomley, Kareem A. Clarcia, Tyler Enright, James Zhangming Fan, Robert A. Freitas Jr., Alan T.K. Godfrey, Si Yue Guo, Aru Hill, Taleana Huff, Mark Jobes, Hadiya Ma, Adam C. Maahs, Oliver MacLean, Steven M. Maley, Michael Marshall, Terry McCallum, Ralph C. Merkle, Mathieu Morin, Ryan Plumadore, Henry Rodriguez, Marc Savoie, Benjamin Scheffel, Janice L. Wong, Damian G. Allis, Jeremy Barton, Michael Drew, Matthew R. Kennedy, Tait Takatani, Marco Taucer, Dusan Vobornik, Ryan Yamachika, Mathieu Durand View PDF HTML (experimental) Abstract:The ability to build atomically precise structures on surfaces with complete control over both atomic placement and chemical bonding remains a central challenge in nanoscale fabrication. Here, we demonstrate simultaneous spatial and chemical control over the mechanosynthetic fabrication of carbon structures. Using inverted-mode STM, C$_2$ units are donated from surface-deposited molecules to pre-patterned reactive sites on a hydrogen-passivated Si(100) surface. We demonstrate single-site C$_2$ donation, spatially patterned multi-site C$_2$ donation, and the stepwise assembly of polyyne structures through successive C-C bond formation. Together, these results establish controlled mechanosynthetic donation as a foundational capability for programmable atomically precise fabrication.

Comments: Supplementary Information is available upon request

Subjects: Materials Science (cond-mat.mtrl-sci) Cite as: arXiv:2605.27250 [cond-mat.mtrl-sci]   (or arXiv:2605.27250v1 [cond-mat.mtrl-sci] for this version)   https://doi.org/10.48550/arXiv.2605.27250 arXiv-issued DOI via DataCite (pending registration) Submission history From: Megan Cowie [view email] [v1] Tue, 26 May 2026 16:28:11 UTC (18,064 KB)