Development of new, high quality functional materials has been at the forefront of condensed matter research. The recent advent of two-dimensional black phosphorus has greatly enriched the material base of two-dimensional electron systems. Significant progress has been made to achieve high mobility black phosphorus two-dimensional electron gas (2DEG) since the development of the first black phosphorus field-effect transistors (FETs)1−4. Here, we reach a milestone in developing high quality black phosphorus 2DEG - the observation of integer quantum Hall (QH) effect. We achieve high quality by embedding the black phosphorus 2DEG in a van der Waals heterostructure close to a graphite back gate; the graphite gate screens the impurity potential in the 2DEG, and brings the carrier Hall mobility up to 6000 cm2V−1s−1. The exceptional mobility enabled us, for the first time, to observe QH effect, and to gain important information on the energetics of the spin-split Landau levels in black phosphorus. Our results set the stage for further study on quantum transport and device application in the ultrahigh mobility regime.
@article{arxiv.1504.07155,
title = {Quantum Hall Effect in Black Phosphorus Two-dimensional Electron Gas},
author = {Likai Li and Fangyuan Yang and Guo Jun Ye and Zuocheng Zhang and Zengwei Zhu and Wen-Kai Lou and Liang Li and Kenji Watanabe and Takashi Taniguchi and Kai Chang and Yayu Wang and Xian Hui Chen and Yuanbo Zhang},
journal= {arXiv preprint arXiv:1504.07155},
year = {2016}
}