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arXiv · 2305.12246

Healing of a Topological Scar: Coordination Defects in a Honeycomb Lattice

Benjamin N Katz·Vincent Crespi
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Abstract

A crystal structure with a point defect typically returns to its ideal local structure upon moving a few bond lengths away from the defect; topological defects such as dislocations or disclinations also heal rapidly in this regard. Here we describe a simple point defect -- a two-fold atom incorporated at the growth edge of a 2D hexagonal honeycomb material -- whose healing may require a defect complex with 50 or more atoms. $\textit{Topologically}$ the two-fold atom disappears into a single 'long bond' between its neighbors, thereby inducing a pentagonal disclination. However, $\textit{chemically}$ this disclination occupies as much physical space as a six-fold ring. This incompatibility of chemistry and topology can cause a ''ringing'' of the Gaussian curvature that creates an expansive healing region and may even spawn a semi-infinite grain boundary propagating outwards from the topological scar.

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Benjamin N Katz, Vincent Crespi. 2023-05-20. Healing of a Topological Scar: Coordination Defects in a Honeycomb Lattice. https://doi.org/10.1016/j.carbon.2025.120193

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