Peramaiyan G, Sankar Raman, Muthuselvam I Panneer, Lee Wei-Li
Institute of Physics, Academia Sinica, Taipei, 10617, Taiwan.
Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan.
Sci Rep. 2018 Apr 23;8(1):6414. doi: 10.1038/s41598-018-24823-z.
We report the extremely large magnetoresistance and anisotropic magnetoresistance in a non-magnetic semimetallic NbAs single crystal. Unsaturated transverse XMR with quadratic field dependence has been observed to be ~3 × 10 % at 2 K and 15 T. Up to 12.5 K, clear Shubnikov de Haas (SdH) quantum oscillations were observed from which two distinct Fermi pockets were identified. The corresponding quantum electronic parameters such as effective cyclotron mass and Dingle temperature were obtained using Lifshitz-Kosevich formula. From the field dependent Hall resistivity at 2 K, carrier concentrations n (n ) = 6.7691 (6.4352) × 10 m and mobilities μ (μ ) = 5.6676 (7.6947) m V s for electrons (e) and holes (h) were extracted using semiclassical two-band model fitting. We observed large anisotropic magnetoresistance about 84%, 75%, and 12% at 0.75 T and 6 K for three different orientations γ, θ and ϕ, respectively, similar to that in several topological semimetallic systems. Magnetic properties of NbAs are similar to the case of graphite, without any phase transition in the temperature range from 5 K to 300 K.
我们报道了非磁性半金属NbAs单晶中的超大磁电阻和各向异性磁电阻。在2K和15T时，观察到具有二次场依赖性的不饱和横向XMR约为3×10%。高达12.5K时，观察到清晰的舒布尼科夫-德哈斯（SdH）量子振荡，从中识别出两个不同的费米面口袋。使用里夫希茨-科塞维奇公式获得了相应的量子电子参数，如有效回旋质量和丁格尔温度。根据2K时的场依赖霍尔电阻率，使用半经典双带模型拟合提取了电子（e）和空穴（h）的载流子浓度n（n）=6.7691（6.4352）×10m和迁移率μ（μ）=5.6676（7.6947）m V s。在0.75T和6K时，对于三个不同取向γ、θ和ϕ，我们分别观察到约84%、75%和12%的大各向异性磁电阻，这与几个拓扑半金属系统中的情况类似。NbAs的磁性与石墨的情况相似，在5K至300K的温度范围内没有任何相变。
