Metal-insulator transition (MIT) is one of the most conspicuous phenomena in correlated electron systems. However such transition has rarely been induced by an external magnetic field as the field scale is normally too small compared with the charge gap. In this paper we present the observation of a magnetic-field-driven MIT in a magnetic semiconductor β-EuP3. Concomitantly, we found a colossal magnetoresistance (CMR) in an extreme way: the resistance drops billionfold at 2 kelvins in a magnetic field less than 3 teslas. We ascribe this striking MIT as a field-driven transition from an antiferromagnetic and paramagnetic insulator to a spin-polarized topological semimetal, in which the spin configuration of Eu2+ cations and spin-orbital coupling (SOC) play a crucial role. As a phosphorene-bearing compound whose electrical properties can be controlled by the application of field, β-EuP3 may serve as a tantalizing material in the basic research and even future electronics.
@article{arxiv.2007.07465,
title = {Field-induced Metal-Insulator Transition in $\beta $-EuP$_3$},
author = {Guangqiang Wang and Guoqing Chang and Huibin Zhou and Wenlong Ma and Hsin Lin and M. Zahid Hasan and Su-Yang Xu and Shuang Jia},
journal= {arXiv preprint arXiv:2007.07465},
year = {2020}
}