Quantum oscillations and transport evidence of topological bands in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>La</mml:mi><mml:mn>3</mml:mn></mml:msub><mml:mi>Mg</mml:mi><mml:msub><mml:mi>Bi</mml:mi><mml:mn>5</mml:mn></mml:msub></mml:mrow></mml:math> single crystals
Xin Han, Hanqi Pi, Dayu Yan, Ruihan Zhang, Yong Li, Xiang Wang, Zhiling Dun, Zhijun Wang, Hai L. Feng, Quansheng Wu, Youguo Shi
Abstract
In this work, we synthesized single crystals of ${\mathrm{La}}_{3}\mathrm{Mg}{\mathrm{Bi}}_{5}$ and systematically investigated their structure, magnetism, and transport properties. ${\mathrm{La}}_{3}\mathrm{Mg}{\mathrm{Bi}}_{5}$ belongs to the ${A}_{3}M{X}_{5}$ family (A = Ca-Ba or rare earth, M = transition materials or Mg, X = chalcogen or pnictogen) and has a quasi-one-dimensional structure. Our magnetic and magnetoresistance measurements show the presence of de Haas--van Alphen (dHvA) and Shubnikov--de Haas (SdH) oscillations. Analysis of these quantum oscillation spectra reveals two major oscillation frequencies (${F}_{\ensuremath{\alpha}}$, ${F}_{\ensuremath{\beta}}$) with corresponding light effective mass and the nearly \ensuremath{\pi} Berry phase for ${F}_{\ensuremath{\alpha}}$, suggesting the nontrivial band topology in ${\mathrm{La}}_{3}\mathrm{Mg}{\mathrm{Bi}}_{5}$, which is further supported by our first-principles calculations. Besides, ${\mathrm{La}}_{3}\mathrm{Mg}{\mathrm{Bi}}_{5}$ manifests a large nonsaturating magnetoresistance and a nonlinear Hall effect at low temperatures. Our results show that ${\mathrm{La}}_{3}\mathrm{Mg}{\mathrm{Bi}}_{5}$ is a topological nontrivial material and a member of the ${A}_{3}M{X}_{5}$ family exhibiting topological properties, providing a platform for further investigation of topological fermionic properties in this family.