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arXiv · 1907.10702

Interlayer quantum transport in Dirac semimetal BaGa$_2$

Sheng Xu·Changhua Bao·Yi-Yan Wang·Peng-Jie Guo·Qiao-He Yu·Lin-Lin Sun·Yuan Su·Kai Liu·Zhong-Yi Lu·Shuyun Zhou·Tian-Long Xia
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Abstract

Quantum limit is quite easy to achieve once the band crossing exists exactly at the Fermi level ($E_F$) in topological semimetals. In multilayered Dirac fermion system, the density of Dirac fermions on the zeroth Landau levels (LLs) increases in proportion to the magnetic field, resulting in intriguing angle- and field-dependent interlayer tunneling conductivity near the quantum limit. BaGa$_2$ is an example of multilayered Dirac semimetal with anisotropic Dirac cone close to $E_F$, providing a good platform to study its interlayer transport properties. In this paper, we report the negative interlayer magnetoresistance (NIMR, I//c and B//c) induced by the tunneling of Dirac fermions on the zeroth LLs of neighbouring Ga layers in BaGa$_2$. When the field deviates from the c-axis, the interlayer resistivity $\rho_{zz}(\theta)$ increases and finally results in a peak with the field perpendicular to the c-axis. These unusual interlayer transport properties (NIMR and resistivity peak with B$\perp$c) are observed together for the first time in Dirac semimetal under ambient pressure and are well explained by the model of tunneling between Dirac fermions in the quantum limit.

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Sheng Xu, Changhua Bao, Yi-Yan Wang, Peng-Jie Guo, Qiao-He Yu, Lin-Lin Sun, Yuan Su, Kai Liu, Zhong-Yi Lu, Shuyun Zhou, Tian-Long Xia. 2019-07-24. Interlayer quantum transport in Dirac semimetal BaGa$_2$. https://doi.org/10.1038/s41467-020-15854-0

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