The search for metallic boron allotropes has attracted great attention in the past decades and recent theoretical works predict the existence of metallicity in monolayer boron. Here, we synthesize the \b{eta}12-sheet monolayer boron on a Ag(111) surface and confirm the presence of metallic boron-derived bands using angle-resolved photoemission spectroscopy. The Fermi surface is composed of one electron pocket at the S point and a pair of hole pockets near the X point, which is supported by the first-principles calculations. The metallic boron allotrope in \b{eta}12 sheet opens the way to novel physics and chemistry in material science.
@article{arxiv.1512.05270,
title = {Direct Evidence of Metallic Bands in a Monolayer Boron Sheet},
author = {Baojie Feng and Jin Zhang and Ro-Ya Liu and Iimori Takushi and Chao Lian and Lan Chen and Kehui Wu and Hui Li and Sheng Meng and Fumio Komori and Iwao Matsuda},
journal= {arXiv preprint arXiv:1512.05270},
year = {2016}
}