By combining angle-resolved photoemission spectroscopy and quantum oscillation measurements, we performed a comprehensive investigation on the electronic structure of LaSb, which exhibits near-quadratic extremely large magnetoresistance (XMR) without any sign of saturation at magnetic fields as high as 40 T. We clearly resolve one spherical and one intersecting-ellipsoidal hole Fermi surfaces (FSs) at the Brillouin zone (BZ) center Γ and one ellipsoidal electron FS at the BZ boundary X. The hole and electron carriers calculated from the enclosed FS volumes are perfectly compensated, and the carrier compensation is unaffected by temperature. We further reveal that LaSb is topologically trivial but share many similarities with the Weyl semimetal TaAs family in the bulk electronic structure. Based on these results, we have examined the mechanisms that have been proposed so far to explain the near-quadratic XMR in semimetals.
@article{arxiv.1604.08142,
title = {Compensated semimetal LaSb with unsaturated magnetoresistance},
author = {L. -K. Zeng and R. Lou and D. -S. Wu and Q. N. Xu and P. -J. Guo and L. -Y. Kong and Y. -G. Zhong and J. -Z. Ma and B. -B. Fu and P. Richard and P. Wang and G. T. Liu and L. Lu and Y. -B. Huang and C. Fang and S. -S. Sun and Q. Wang and L. Wang and Y. -G. Shi and H. M. Weng and H. -C. Lei and K. Liu and S. -C. Wang and T. Qian and J. -L. Luo and H. Ding},
journal= {arXiv preprint arXiv:1604.08142},
year = {2016}
}