Via angular Shubnikov-de Hass (SdH) quantum oscillations measurements, we determine the Fermi surface topology of NbAs, a Weyl semimetal candidate. The SdH oscillations consist of two frequencies, corresponding to two Fermi surface extrema: 20.8 T (α-pocket) and 15.6 T (β-pocket). The analysis, including a Landau fan plot, shows that the β-pocket has a Berry phase of π and a small effective mass ∼0.033 m0, indicative of a nontrivial topology in momentum space; whereas the α-pocket has a trivial Berry phase of 0 and a heavier effective mass ∼0.066 m0. From the effective mass and the β-pocket frequency we determine that the Weyl node is 110.5 meV from the chemical potential. A novel electron-hole compensation effect is discussed in this system, and its impact on magneto-transport properties is addressed. The difference between NbAs and other monopnictide Weyl semimetals is also discussed.
@article{arxiv.1506.01751,
title = {Electron-hole compensation effect between topologically trivial electrons and nontrivial holes in NbAs},
author = {Yongkang Luo and N. J. Ghimire and M. Wartenbe and Hongchul Choi and M. Neupane and R. D. McDonald and E. D. Bauer and Jianxin Zhu and J. D. Thompson and F. Ronning},
journal= {arXiv preprint arXiv:1506.01751},
year = {2015}
}