Extended Kohler’s Rule of Magnetoresistance
Jing Xu, Fei Han, Ting-Ting Wang, Laxman R. Thoutam, Samuel E. Pate, Mingda Li, Xufeng Zhang, Yong-Lei Wang, Roxanna Fotovat, Ulrich Welp, Xiuquan Zhou, Wai-Kwong Kwok, Duck Young Chung, Mercouri G. Kanatzidis, Zhi-Li Xiao
Abstract
A notable phenomenon in topological semimetals is the violation of Kohler's rule, which dictates that the magnetoresistance MR obeys a scaling behavior of MR fH= 0 , where MR H - 0 = 0 and H is the magnetic field, with H and 0 being the resistivity at H and zero field, respectively. Here, we report a violation originating from thermally induced change in the carrier density. We find that the magnetoresistance of the Weyl semimetal TaP follows an extended Kohler's rule MR fH=n T 0 , with n T describing the temperature dependence of the carrier density. We show that n T is associated with the Fermi level and the dispersion relation of the semimetal, providing a new way to reveal information on the electronic band structure. We offer a fundamental understanding of the violation and validity of Kohler's rule in terms of different temperature responses of n T . We apply our extended Kohler's rule to BaFe 2 As 1-x P x 2 to settle a long-standing debate on the scaling behavior of the normal-state magnetoresistance of a superconductor, namely, MR tan 2 H , where H is the Hall angle. We further validate the extended Kohler's rule and demonstrate its generality in a semiconductor, InSb, where the temperature-dependent carrier density can be reliably determined both theoretically and experimentally.