Real-Space Plasmon Imaging Reveals Modified Electronic Structure of Gold at the Monolayer Limit
Abstract
Atomically thin materials exhibit electronic and optical properties distinct from their three-dimensional counterparts. For metals, particularly gold, monolayer studies remain largely unexplored due to fabrication and characterisation challenges. Here we report the first optical study of a stable quasi-freestanding gold monolayer formed by Au intercalation between graphene and SiC. Mid-infrared nanoimaging reveals plasmon-polaritons with wavelengths nearly an order of magnitude shorter than free-space light. Analysis of their dispersion using a Drude model yields a relaxation time of fs, comparable to bulk gold, and a Drude weight of mSeV, nearly twice the bulk expectation. These results establish monolayer gold as a two-dimensional metal, opening opportunities for nanoscale photonics, plasmonics and ultra-thin electronics.
Cite
@article{arxiv.2603.05030,
title = {Real-Space Plasmon Imaging Reveals Modified Electronic Structure of Gold at the Monolayer Limit},
author = {Andrei Bylinkin and Philippe Roelli and Naveen Shetty and Rositsa Yakimova and Ulrich Starke and Camilla Coletti and Stiven Forti and Alexei Zakharov and Vyacheslav M. Silkin and Samuel Lara-Avila and Rainer Hillenbrand},
journal= {arXiv preprint arXiv:2603.05030},
year = {2026}
}