arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.08359cond-mat.str-el
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含多狄拉克费米子的BaSn3超导体中的de Hass-van Alphen量子振荡

The de Hass-van Alphen quantum oscillations in BaSn3 superconductor with multiple Dirac fermions

Gaoning Zhang, Xianbiao Shi, Xiaolei Liu, Wei Xia, Hao Su, Leiming Chen, Xia Wang, Na Yu, Zhiqiang Zou, Weiwei Zhao, Yanfeng Guo

摘要:

通过测量de Hass-van Alphen效应和计算电子能带结构,研究了BaSn_3超导体的体费米面,其转变温度为~ 4.4 K.当磁场B同时垂直于(100)和(001)面时,观察到强烈的de Haas-van Alphen(dHvA)量子振荡.我们的分析揭示了当B垂直于(100)时,在量子振荡中施加的非平凡Berry相位,其中两个基频分别为31.5 T和306.7 T,这可能是由形成II型Dirac点的带的两个相应的空穴袋引起的。从头计算结果表明,II型狄拉克点设置和倾斜沿高对称的K-H线的布里渊区,约0.13 eV以上的费米能级的支持。此外,计算还揭示了在高对称性的Γ-A方向上的另外两个I型狄拉克点,但略低于费米能级。结果表明,BaSn 3不仅是研究单一材料中不同类型狄拉克费米子的奇异性质,而且是研究非平凡拓扑态与超导性之间的相互作用的良好平台。

英文摘要:

By measuring the de Hass-van Alphen effect and calculating the electronic band structure, we have investigated the bulk Fermi surface of the BaSn3 superconductor with a transition temperature of ~ 4.4 K. Striking de Haas-van Alphen (dHvA) quantum oscillations are observed when the magnetic field B is perpendicular to both (100) and (001) planes. Our analysis unveiled nontrivial Berry phase imposed in the quantum oscillations when B is perpendicular to (100), with two fundamental frequencies at 31.5 T and 306.7 T, which likely arise from two corresponding hole pockets of the bands forming a type-II Dirac point. The results are supported by the ab initio calculations indicating a type-II Dirac point setting and tilting along the high symmetric K-H line of the Brillouin zone, about 0.13 eV above the Fermi level. Moreover, the calculations also revealed other two type-I Dirac points on the high symmetric Γ-A direction, but slightly far below the Fermi level. The results demonstrate BaSn3 as an excellent platform for the study of not only exotic properties of different types of Dirac fermions in a single material, but also the interplay between nontrivial topological states and superconductivity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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