Intervalence Plasmons in Boron-Doped Diamond
Abstract
Doped semiconductors can exhibit metallic-like properties ranging from superconductivity to tunable localized surface plasmon resonances. Diamond is a wide-bandgap semiconductor that is rendered electronically active by incorporating a hole dopant, boron. While the effects of boron doping on the electronic band structure of diamond are well-studied, any link between charge carriers and plasmons, has never been shown. Here, we report intervalence plasmons in boron-doped diamond, defined as collective electronic excitations between the valence subbands, opened up by the presence of holes. Evidence for these low-energy excitations is provided by valence electron energy loss spectroscopy and near-field infrared spectroscopy. The measured spectra are subsequently reproduced by first-principles calculations based on the contribution of intervalence band transitions to the dielectric function. Our calculations also reveal that the real part of the dielectric function exhibits a crossover characteristic of metallicity. These results suggest a new mechanism for inducing plasmon-like behavior in doped semiconductors, and the possibility of attaining such properties in diamond, a key emerging material for quantum information technologies.
Cite
@article{arxiv.2403.12221,
title = {Intervalence Plasmons in Boron-Doped Diamond},
author = {Souvik Bhattacharya and Jonathan Boyd and Sven Reichardt and Valentin Allard and Amir Hossein Talebi and Nicolò Maccaferri and Olga Shenderova and Aude L. Lereu and Ludger Wirtz and Giuseppe Strangi and R. Mohan Sankaran},
journal= {arXiv preprint arXiv:2403.12221},
year = {2025}
}