Reconstruction of 2D metal in the nano-space between graphene and SiC

03/25/2026 / Announcements

High resolution STM image and calculated DFT of reconstructed monolayer silver under graphene. From V. D. Pham et al., Strain-induced reconstruction in two-dimensional silver intercalated between graphene and SiC, Physical Review Materials. © Authors, published under CC BY 4.0. https://doi.org/10.1103/pc8w-hz4t

Selected as an Editors' Suggestion in Physical Review Materials, March 2026

Atomically thin metals confined between graphene and SiC represent a compelling materials platform. In this reduced-dimensionality system, 2D metals can exhibit unusual physical properties with potential relevance to electronic devices and quantum technology. Despite this promise, the structural behavior of metals confined to this nano-space has remained largely unexplored.

A new study led by Van Dong Pham at the Paul-Drude-Institut fur Festkorperelektronik (PDI), in collaboration with Penn State University and Juniata College, Huntingdon, Pa., sheds new light on this problem. Focusing on monolayer silver epitaxially grown on SiC (0001), the team shows how strain at the silver-SiC interface drives the formation of a non-ideal silver structure, specifically a one-dimensional reconstruction known as a Frenkel-Kontorova domain. This strain arises from competing interactions between silver-SiC bonding and silver-silver interatomic forces, producing a long-range structural modulation and a characteristic electronic state at 0.75 eV above the Fermi level. The findings were obtained using cryogenic scanning tunneling microscopy, supported by first-principles density functional theory calculations.

The results uncover the interplay between atomic structure and electronic properties in this confined system and open new pathways for engineering 2D metals at the nanoscale. The work has been published in Physical Review Materials and selected as an Editors' Suggestion, a distinction awarded to a small fraction of published papers that the editors consider particularly significant and of broad interest to the community.

Title: Strain-induced reconstruction in two-dimensional silver intercalated between graphene and SiC
Authors: V. D. Pham, B. Zheng, A. Jain, C. Dong, L-S. Lu, Z. W. Henshaw, W. H. Blades, J. A. Robinson, V. H. Crespi, A. Trampert, R. Engel-Herbert
Source: Phys. Rev. Materials 10, 034003 – Published 13 March, 2026
DOI: https://doi.org/10.1103/pc8w-hz4t

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