2018/02/28 by Sihang Liang, Jingjing Lin, Satya Kushwaha +6 · 1 citation
Materials Science · Physics and Astronomy · #Anomaly (physics) #Chemical and Physical Properties of Materials #Current (fluid) #Current density #Distortion (music) #Electrical resistivity and conductivity #Enhanced Data Rates for GSM Evolution #Magnetic field #Magnetoresistance #Parametric statistics #Quantum Mechanics and Non-Hermitian Physics #Topological Materials and Phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevx.8.031002
published as Phys. Rev. X 8, 031002 (2018) · 17 pages, 8 figures, new co-authors added, new Fig. 6a added. In press, PRX
openalex created_date 2018/02/23 · arxiv created 2018/06/14 · openalex publication_date 2018/07/03 · arxiv updated 2018/07/11 · openalex updated_date 2026/08/06
In the Dirac-Weyl semimetal, the chiral anomaly appears as an "axial" current arising from charge pumping between the lowest (chiral) Landau levels of the Weyl nodes, when an electric field is applied parallel to a magnetic field B. Evidence for the chiral anomaly was obtained from the longitudinal magnetoresistance (LMR) in Na 3 Bi and GdPtBi. However, current-jetting effects (focusing of the current density J) have raised general concerns about LMR experiments. Here, we implement a litmus test that allows the intrinsic LMR in Na 3 Bi and GdPtBi to be sharply distinguished from pure current-jetting effects (in pure Bi). Current jetting enhances J along the mid-line (spine) of the sample while decreasing it at the edge. We measure the distortion by comparing the local voltage drop at the spine (expressed as the resistance R spine ) with that at the edge (R edge ). In Bi, R spine sharply increases with B, but R edge decreases (jetting effects are dominant). However, in Na 3 Bi and GdPtBi, both R spine and R edge decrease (jetting effects are subdominant). A numerical simulation allows the jetting distortions to be removed entirely. We find that the intrinsic longitudinal resistivity xx B in Na 3 Bi decreases by a factor of 10.9 between B 0 and 10 T. A second litmus test is obtained from the parametric plot of the planar angular magnetoresistance. These results considerably strengthen the evidence for the intrinsic nature of the chiral-anomaly-induced LMR. We briefly discuss how the squeeze test may be extended to test ZrTe 5 .