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Interlayer quantum transport in Dirac semimetal BaGa2
Sheng Xu1, Changhua Bao2, Peng-Jie Guo1
1Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872, P. R. China.
Nature Communications
|May 14, 2020
Summary
Topological semimetals like BaGa2 exhibit negative interlayer magnetoresistance due to Dirac fermion tunneling. This phenomenon, observed near the quantum limit, is sensitive to magnetic field orientation.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- Topological semimetals feature band crossings at the Fermi level (EF).
- Multilayered Dirac fermion systems show field-dependent interlayer tunneling conductivity.
- BaGa2 is a multilayered Dirac semimetal with a quasi-2D Dirac cone at EF.
Purpose of the Study:
- Investigate interlayer transport properties of BaGa2.
- Study the quantum limit phenomena in multilayered Dirac semimetals.
- Explore the role of Dirac fermion tunneling in interlayer conductivity.
Main Methods:
- Experimental measurement of interlayer resistivity in BaGa2 under varying magnetic fields and angles.
- Theoretical modeling of Dirac fermion tunneling between Landau levels.
- Analysis of angle- and field-dependent magnetoresistance.
Main Results:
- Observed negative interlayer magnetoresistance in BaGa2 attributed to Dirac fermion tunneling.
- Interlayer resistivity ρzz(θ) increases with field deviation from the c-axis, peaking at perpendicular fields.
- Unusual interlayer transport properties consistent with tunneling between zeroth Landau levels (LLs).
Conclusions:
- BaGa2 serves as a platform to study quantum limit transport in Dirac semimetals.
- The observed negative magnetoresistance is explained by Dirac fermion tunneling in the quantum limit.
- Angle-dependent interlayer resistivity provides insights into quantum phenomena in multilayered systems.
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