The proximity-effect, whereby materials in contact appropriate each others electronic-properties, is widely used to induce correlated states, such as superconductivity or magnetism, at heterostructure interfaces. Thus far however, demonstrating the existence of proximity-induced charge-density-waves (PI-CDW) proved challenging. This is due to competing effects, such as screening or co-tunneling into the parent material, that obscured its presence. Here we report the observation of a PI-CDW in a graphene layer contacted by a 1T-TaS2 substrate. Using scanning tunneling microscopy (STM) and spectroscopy (STS) together with theoretical-modeling, we show that the coexistence of a CDW with a Mott gap in 1T-TaS2 coupled with the Dirac-dispersion of electrons in graphene, makes it possible to unambiguously demonstrate the PI-CDW by ruling out alternative interpretations. Furthermore, we find that the PI-CDW is accompanied by a reduction of the Mott gap in 1T-TaS2 and show that the mechanism underlying the PI-CDW is well-described by short-range exchange-interactions that are distinctly different from previously observed proximity effects.
@article{arxiv.2311.10606,
title = {Revealing the Charge Density Wave Proximity Effect in Graphene on 1T-TaS$_2$},
author = {Nikhil Tilak and Michael Altvater and Sheng-Hsiung Hung and Choong-Jae Won and Guohong Li and Taha Kaleem and Sang-Wook Cheong and Chung-Hou Chung and Horng-Tay Jeng and Eva Y. Andrei},
journal= {arXiv preprint arXiv:2311.10606},
year = {2024}
}
Comments
35 pages, 16 figures. arXiv admin note: text overlap with arXiv:2201.09195