Plasmon Engineering in Intercalated 2H-TaS$_2$

TL;DR

This study demonstrates that transition metal intercalation in layered 2H-TaS2 can effectively modify plasmonic responses by reshaping electronic structures, leading to controlled damping and suppression of plasmon modes.

Contribution

It introduces intercalation as a novel chemical strategy to engineer plasmonic properties and dissipation in layered quantum materials.

Findings

Fe and Co intercalation reshape electronic structure via orbital hybridization.

Intercalation introduces low energy excitations that dampen plasmons.

First-principles calculations show a transition from collective to overdamped response.

Abstract

Plasmons in low dimensional materials provide a powerful platform for nanoscale control of light matter interactions, yet strategies to tailor their coherence and dissipation remain limited. Here, we demonstrate that transition metal intercalation offers a fundamentally distinct route to engineer plasmonic response in layered materials. By combining high-resolution core-level photoemission spectroscopy with first-principles calculations, we show that Fe and Co intercalation in 2H-TaS2 does not act as conventional electron doping, but instead reshapes the low energy electronic structure through orbital hybridization and structural reconstruction. This process introduces a dense continuum of low energy excitations that efficiently damp and ultimately suppress the plasmon mode. First principle calculations of the energy loss function reveal a transition from a well defined collective excitation to an overdamped response, signaling the breakdown of coherent charge dynamics. Our results establish intercalation as a chemically controlled pathway to tune plasmon losses and dielectric response in quantum van der Waals materials, providing a new design principle for plasmonic and optoelectronic functionalities at the nanoscale.