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Strain-induced reconstruction in two-dimensional silver intercalated between graphene and SiC

Van Dong Pham1,*,†, Boyang Zheng2,3,*, Arpit Jain4, Chengye Dong3,4,5, Li-Syuan Lu4, Zachary W. Henshaw6, William H. Blades6, Joshua A. Robinson3,4,5,7, Vincent H. Crespi2 et al.

Achim Trampert1 and Roman Engel-Herbert1

  • *These authors contributed equally to the work.
  • †Contact author: pham@pdi-berlin.de
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Phys. Rev. Materials 10, 034003 – Published 13 March, 2026

DOI: https://doi.org/10.1103/pc8w-hz4t

Abstract

The realization of air-stable two-dimensional (2D) metals confined at the interface between graphene and SiC has attracted significant attention owing to their distinct properties compared to their bulk counterparts. In this work, we identify two distinct structural phases in a monolayer silver intercalated between graphene and SiC: (i) a moiré pattern arising from the lattice mismatch between graphene and monolayer silver and (ii) a striped reconstruction formed through the interaction with the underlying SiC. Using cryogenic scanning tunneling microscopy combined with density functional theory, we elucidate the origin of the silver striped reconstruction. Driven by the competition between the silver-SiC and the silver-silver interactions within a monolayer, the silver atoms form a one-dimensional Frenkel-Kontorova domain, in which an (n+1)×√3 silver supercell accommodates an n×√3 supercell (n=20) of the underlying SiC, which partially relieves tensile strain, otherwise imposed by ideal epitaxy. The strain-induced reconstruction creates a long-range modulation of 2D silver electronic density, giving rise to an electronic state at ∼0.75eV above the Fermi level in the transition regions between different silver-SiC registries. These findings uncover the important interplay between the structural and electronic properties of intercalated 2D metals and the underlying SiC substrate, providing new insights into substrate-mediated reconstruction and electronic modulation at confined interfaces.

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Phys. Rev. Materials 10, 034003– Published 13 March, 2026
  • Received 8 December 2025
  • Accepted 18 February 2026
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