Quantitative analysis of chiral anomaly induced negative magnetoresistance in nodal-line semimetal SrAs₃

Recently, three-dimensional topological nodal-line semimetals has been reported frequently as a new class of quantum materials. In nodal-line semimetals, the conduction and the valence bands contact with each other. The band crossing points around the Fermi level form a closed loop. Chiral anomaly is one of the property of nodal-line semimetal. The phenomenon of chiral anomaly in transport measurement is negative magnetoresistance(NMR) when current is parallel with magnetic field. The electronic conductivity induced by chiral anomaly is: σ_zz=e^2/(4π^2 hbar c) v/c ((eB)^2 v^2)/μ^2 τ
[1]. The v is fermi velocity; μ is chemistry potential and τ is scattering time. The τ depends on the magnetic field and temperature. When the magnetic is higher than the quantum limit, the , the NMR will saturate.
Among the predicted nodal-line semimetals[2], SrAs₃ has high mobility and low fermi energy, which makes this material an ideal platform to research the behavior of NMR with magnetic field and temperature. Under 31.5 T, we observed the process from NMR appeared to saturated. And analyzed the behavior of NMR quantitatively. Combined with the result from PPMS, we also got the temperature dependence of τ.