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arXiv · 1901.04932

Quasi 1D topological nodal vortex line phase in doped superconducting 3D Dirac Semimetals

Shengshan Qin·Lunhui Hu·Congcong Le·Jinfeng Zeng·Fu-chun Zhang·Chen Fang·Jiangping Hu
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Abstract

We study the vortex bound states in three dimensional (3D) superconducting Dirac semimetals with time reversal symmetry. Assuming two Dirac points on the kz-axis and bulk s-wave superconductivity, with a quantum vortex line parallel to the z-direction, we find that the superconducting vortex line has a robust quasi-1D nodal phase. The nodal phase stems from the symmetry protected Dirac points in the normal state bands, and it can be characterized by a topological index (ν; n) at kz = 0 and kz = π, where νis the Z2 topological invariant for a 0D class-D system and n is the Z topological invariant for a 0D class-A system according to the Altland- Zirnbauer classification. Based on the topological index, we find that vortex end Majorana zero mode can coexist with the quasi-1D nodal phase in certain kinds of Dirac semimetals. The influence of the symmetry breaking perturbations on the quasi-1D nodal phase is also analyzed. Finally, we discuss the possible material realization of such nodal vortex line state.

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Shengshan Qin, Lunhui Hu, Congcong Le, Jinfeng Zeng, Fu-chun Zhang, Chen Fang, Jiangping Hu. 2019-02-01. Quasi 1D topological nodal vortex line phase in doped superconducting 3D Dirac Semimetals. https://doi.org/10.1103/physrevlett.123.027003

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