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arXiv · 2001.08359

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
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Abstract

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.

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Gaoning Zhang, Xianbiao Shi, Xiaolei Liu, Wei Xia, Hao Su, Leiming Chen, Xia Wang, Na Yu, Zhiqiang Zou, Weiwei Zhao, Yanfeng Guo. 2020-01-23. The de Hass-van Alphen quantum oscillations in BaSn3 superconductor with multiple Dirac fermions. https://arxiv.org/abs/2001.08359

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