Metal-Insulator Transition and Emergent Gapped Phase in the Surface-Doped 2D Semiconductor 2H-MoTe$_2$
Abstract
Artificially created two-dimensional (2D) interfaces or structures are ideal for seeking exotic phase transitions due to their highly tunable carrier density and interfacially enhanced many-body interactions. Here, we report the discovery of a metal-insulator transition (MIT) and an emergent gapped phase in the metal-semiconductor interface that is created in 2H-MoTe via alkali-metal deposition. Using angle-resolved photoemission spectroscopy, we found that the electron-phonon coupling is strong at the interface as characterized by a clear observation of replica shake-off bands. Such strong electron-phonon coupling interplays with disorder scattering, leading to an Anderson localization of polarons which could explain the MIT. The domelike emergent gapped phase could then be attributed to a polaron extended state or phonon-mediated superconductivity. Our results demonstrate the capability of alkali-metal deposition as an effective method to enhance the many-body interactions in 2D semiconductors. The surface-doped 2H-MoTe is a promising candidate for realizing polaronic insulator and high- superconductivity.
Keywords
Cite
@article{arxiv.2103.07596,
title = {Metal-Insulator Transition and Emergent Gapped Phase in the Surface-Doped 2D Semiconductor 2H-MoTe$_2$},
author = {T. T. Han and L. Chen and C. Cai and Z. G. Wang and Y. D. Wang and Z. M. Xin and Y. Zhang},
journal= {arXiv preprint arXiv:2103.07596},
year = {2021}
}
Comments
11 pages, 4 figures, See Supplemental Material at http://link.aps.org/ supplemental/10.1103/PhysRevLett.126.106602