Coexistence of Surface Superconducting and Three-Dimensional Topological Dirac States in Semimetal KZnBi
We report the discovery of a new three-dimensional (3D) topological Dirac semimetal (TDS) material KZnBi, coexisting with a naturally formed superconducting state on the surface under ambient pressure. Using photoemission spectroscopy together with first-principles calculations, a 3D Dirac state wit...
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Autores principales: | , , , , , , , , , , , , , , , , , |
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Formato: | article |
Lenguaje: | EN |
Publicado: |
American Physical Society
2021
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Materias: | |
Acceso en línea: | https://doaj.org/article/9551a0a5cb9244b2ad254300c638487a |
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Sumario: | We report the discovery of a new three-dimensional (3D) topological Dirac semimetal (TDS) material KZnBi, coexisting with a naturally formed superconducting state on the surface under ambient pressure. Using photoemission spectroscopy together with first-principles calculations, a 3D Dirac state with linear band dispersion is identified. The characteristic features of massless Dirac fermions are also confirmed by magnetotransport measurements, exhibiting an extremely small cyclotron mass of m^{*}=0.012 m_{0} and a high Fermi velocity of v_{F}=1.04×10^{6} m/s. Interestingly, superconductivity occurs below 0.85 K on the (001) surface, while the bulk remains nonsuperconducting. The captured linear temperature dependence of the upper critical field suggests the possible non-s-wave character of this surface superconductivity. Our discovery serves a distinctive platform to study the interplay between 3D TDS and the superconductivity. |
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