2019/07/27 by Ming-Xun Deng, Yanyan Yang, Yan-Yan Yang +7
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Anomaly (physics) #Charge (physics) #Chiral anomaly #Combinatorics #Condensed matter physics #Dirac (video compression format) #Fermion #Graphene research and applications #Magnetic field #Physics #Quantum mechanics #Semimetal #Spin (aerodynamics) #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.100.235105
published as Phys. Rev. B 100, 235105 (2019) · 5 pages, 2 figures
arxiv created 2019/07/27 · openalex created_date 2019/08/13 · openalex publication_date 2019/12/03 · arxiv updated 2019/12/10 · openalex updated_date 2026/08/05
Recently, a class of Dirac semimetals, such as Na3Bi and Cd2As3, is discovered to carry ℤ2 monopole charges. We present an experimental mechanism to realize the ℤ2 anomaly in regard to the ℤ2 topological charges and propose to probe it by magnetotransport measurements. In analogy to the chiral anomaly in Weyl semimetals, the acceleration of electrons by a spin bias along the magnetic field can create a ℤ2 charge imbalance between the Dirac points, the relaxation of which contributes measurable positive longitudinal spin magnetoconductivity (LSMC) to the system. The ℤ2 anomaly induced LSMC is a spin version of the longitudinal magnetoconductivity (LMC) due to the chiral anomaly, which possesses all characters of the chiral anomaly induced LMC. While the chiral anomaly in the topological Dirac semimetal is very sensitive to local magnetic impurities, the ℤ2 anomaly is found to be immune to local magnetic disorder. It is further demonstrated that the quadratic or linear field dependence of the positive LMC is not unique to the chiral anomaly. Base on this, we argue that the periodic-in-1/B quantum oscillations superposed on the positive LSMC can serve as a fingerprint of the ℤ2 anomaly in topological Dirac semimetals.