2016/04/13 by Kefeng Wang, D. Graf, C. Petrovic
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.87.235101
published as Phys. Rev. B 87, 235101 (2013) · 7 pages, 7 figures. arXiv admin note: text overlap with arXiv:1204.1333
arxiv created 2016/04/13 · arxiv updated 2016/04/14
We report quasi-two-dimensional Dirac fermions and quantum magnetoresistance in LaAgBi2. The band structure shows several narrow bands with nearly linear energy dispersion and Dirac-cone-like points at the Fermi level. The quantum oscillation experiments revealed one quasi-two-dimensional Fermi pocket and another complex pocket with small cyclotron resonant mass. The in-plane transverse magnetoresistance exhibits a crossover at a critical field B^* from semiclassical weak-field B2 dependence to the high-field unsaturated linear magnetoresistance which is attributed to the quantum limit of the Dirac fermions. Our results suggest the existence of quasi 2D Dirac fermions in rare-earth based layered compounds with two-dimensional double-sized Bi square nets, similar to (Ca,Sr)MnBi2, irrespective of magnetic order.