Nontopological chiral chemical potential due to the Zeeman field in magnetic Weyl semimetals

Letter

Nontopological chiral chemical potential due to the Zeeman field in magnetic Weyl semimetals

Yi-Hang Lei, Yong-Long Zhou, Hou-Jian Duan, Ming-Xun Deng, Zhi-En Lu, and Rui-Qiang Wang
Phys. Rev. B 104, L121117 – Published 27 September 2021

ABSTRACT

As condensed-matter manifestations of the chiral anomaly, the coexistence of positive longitudinal magnetoconductivity (LMC) and the planar Hall effect (PHE) is regarded as a characteristic transport signal for the Weyl semimetal (WSM) phase. By including a finite Newtonian mass into the general linearized WSM model, we derive an analytical expression for the chiral chemical potential, which includes a topological term of the chiral anomaly and a nontopological term. The nontopological term stems from the Zeeman-field-induced tilt of the Weyl cones, which breaks the symmetry of the fermion filling between the Weyl valleys of opposite chiralities and further leads to a chiral chemical potential EB, much as the effect of the chiral anomaly. We demonstrate that the resulting LMC is positive and can coexist with the PHE without invoking the mechanism of the chiral anomaly. Hence, the chiral chemical potential might not be exclusively respected to the chiral anomaly. Experimentally, one can distinguish the chiral anomaly from the proposed tilt mechanism by inspecting the dependence of magnetoconductivity on the Fermi energy.

  • Received 28 December 2020

  • Accepted 20 September 2021

DOI:https://doi.org/10.1103/PhysRevB.104.L121117

AUTHORS & AFFILIATIONS

Yi-Hang Lei1Yong-Long Zhou1Hou-Jian Duan1,2Ming-Xun Deng1,2,*Zhi-En Lu3, and Rui-Qiang Wang1,2,†

  • 1Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006, China

  • 2Guangdong-Hong Kong Joint Laboratory of Quantum Matter, South China Normal University, Guangzhou 510006, China

  • 3Guangzhou City Construction College, Guangzhou 510925, China