We report transport measurement in zero and applied magnetic field on a single crystal of NbAs. Transverse and longitudinal magnetoresistance in the plane of this tetragonal structure does not saturate up to 9 T. In the transverse configuration ($H \parallel c$, $I \perp c$) it is 230,000 \% at 2 K. The Hall coefficient changes sign from hole-like at room temperature to electron-like below $\sim$ 150 K. The electron carrier density and mobility calculated at 2 K based on a single band approximation are 1.8 x 10$^{19}$ cm$^{-3}$ and 3.5 x 10$^{5}$ cm$^2$/Vs, respectively. These values are similar to reported values for TaAs and NbP, and further emphasize that this class of noncentrosymmetric, transition-metal monopnictides is a promising family to explore the properties of Weyl semimetals and the consequences of their novel electronic structure.
Tunable chiral anomaly in electron magnetotransport in the Weyl semimetallic Pb$_{1-x}$Sn$_x$Te:Cr alloy
Institute of Low Temperature and Structure Research, Polish Academy of Sciences(波兰科学院低温结构研究所);ENSEMBLE3 Centre of Excellence for Nanophotonics, Advanced Materials and Novel Crystal Growth-Based Technologies(ENSEMBLE3纳米光子学、先进材料及新型晶体生长技术卓越中心)
Electrical and thermal magnetotransport in altermagnetic CrSb
Helmholtz-Zentrum Dresden-Rossendorf(德累斯顿罗森多夫亥姆霍兹中心);Würzburg-Dresden Cluster of Excellence ctd.qmat(维尔茨堡-德累斯顿卓越集群 ctd.qmat);Technische Universität Dresden(德累斯顿工业大学);Czech Academy of Sciences(捷克科学院);Institute of Physics, Czech Academy of Sciences(捷克科学院物理研究所);Charles University(查理大学);Faculty of Mathematics and Physics, Charles University(查理大学数学与物理学院);Leibniz Institute for Solid State and Materials Research, IFW Dresden(德累斯顿IFW莱布尼兹固态与材料研究研究所);ISIS Neutron and Muon Source, STFC Rutherford Appleton Laboratory(STFC拉瑟福德阿普尔顿实验室ISIS中子与μ子源)
Anisotropic magnetotransport of electron gases at SrTiO3 (111) and (110) surfaces with high mobility
用Ar+辐照在SrTiO_3(001)、(110)和(111)取向的表面上产生了电子气,(001)、(110)和(111)取向的表面具有完全的金属行为,低温迁移率分别高达5500 cm ~ 2 V ~(-1)s ~(-1)、1300 cm ~ 2 V ~(-1)s ~(-1)和8600 cm ~ 2 V ~(-1)s ~(-1)。研究了电流沿不同晶轴方向施加时样品的面内各向异性磁电阻(AMR),以消除洛伦兹力效应。AMR显示出与晶轴的固定取向一致的特征,对于(001)-、(110)和(111)-表面分别具有4倍、2倍和近6倍对称性,与电流方向无关。这些特征可能是由二维费米面的自旋轨道织构极化引起的。此外,还观察到了(111)面的6- 2重对称破缺.我们的结果表明二维电子结构的对称性对电子气在STO表面的输运行为的影响。
2D layered transport properties from topological insulator Bi$_2$Se$_3$ single crystals and micro flakes
拓扑绝缘体如Bi $_2$ Se $_3$的低场磁输运测量对于通过对电导率的量子修正(如弱反局域化)来揭示拓扑表面态的性质是重要的。最近,各种各样的高场磁输运性能的制度,高电子密度($\sim10^{19}$ cm $^{-3}$)的报道,这可能与额外的二维层状导电性,阻碍了识别的拓扑表面状态。在这里,我们报告的量子校正的电子传导占主导地位的表面状态的半导体的情况下,这可以分析的Hikami-Larkin-Nagaoka模型的两个耦合表面的情况下,强自旋轨道相互作用。然而,在类金属的情况下,这种分析失败,需要考虑额外的二维贡献。Shubnikov-de Haas振荡和量子化霍尔电阻证明是二维层状金属行为的强有力的迹象。高品质的Bi $_2$ Se $_3$单晶剥离的宏观和微观薄片的温度依赖性的磁输运性质相结合的高分辨率透射电子显微镜和能量色散X射线光谱,确认的结构和化学计量。角分辨光电子能谱证明了在拓扑绝缘态下,晶体具有单狄拉克锥表面态和定义明确的体带隙。空间分辨的核心水平的光电子显微镜证明了表面的稳定性。
Optimized growth of large-size, high quality $\text{ZrTe}_5$ single crystals enabling clear quantum oscillations in electrical transport
Tsung-Dao Lee Institute, Shanghai Jiao Tong University(上海交大李政道研究所);School of Physics and Astronomy, Shanghai Jiao Tong University(上海交通大学物理与天文学院);State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University(清华大学物理系低维量子物理国家重点实验室);Frontier Science Center for Quantum Information(量子信息前沿科学中心)