Atomically thin transition metal dichalcogenides can exhibit markedly different electronic properties compared to their bulk counterparts. In the case of NbSe2, the question of whether its charge density wave (CDW) phase is enhanced in the monolayer limit has been the subject of intense debate, primarily due to the difficulty of decoupling this order from its environment. Here, we address this challenge by using a misfit crystal that comprises NbSe2 monolayers separated by SnSe rock-salt spacers, a structure that allows us to investigate a monolayer crystal embedded in a bulk matrix. We establish an effective monolayer electronic behavior of the misfit crystal by studying its transport properties and visualizing its electronic structure by angle-resolved photoemission measurements. We then investigate the emergence of the CDW by tracking the temperature dependence of its collective modes. Our findings reveal a nearly sixfold enhancement in the CDW transition temperature, providing compelling evidence for the profound impact of dimensionality on charge order formation in NbSe2.
@article{arxiv.2308.02772,
title = {Probing charge order of monolayer NbSe$_2$ within a bulk crystal},
author = {Doron Azoury and Edoardo Baldini and Aravind Devarakonda and Jiarui Li and Shiang Fang and Pheona Williams and Riccardo Comin and Joseph Checkelsky and Nuh Gedik},
journal= {arXiv preprint arXiv:2308.02772},
year = {2023}
}