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Three-terminal Weyl complex with double surface arcs in a cubic lattice.
- Source :
- NPJ Computational Materials; 7/3/2020, Vol. 6 Issue 1, p1-7, 7p
- Publication Year :
- 2020
-
Abstract
- Exploring unconventional topological quasiparticles and their associated exotic physical properties has become a hot topic in condensed matter physics, thus stimulating extensive interest in recent years. Here, in contrast to the double-Weyl phonons (the topological chiral charge +2) in the trigonal and hexagonal crystal systems, we propose that the unconventional double-Weyl without counterparts in high-energy physics can emerge in the phonons of cubic structures, i.e., SrSi<subscript>2</subscript>. Employing a two-band k ⋅ p Hamiltonian, we prove that the quadratic double-Weyl nodes are protected by the fourfold screw rotational symmetry C ̃ 4 . Strikingly, we find that the surface arcs are terminated with the Weyl nodes that possess unequal topological charges with opposite sign (i.e., +2 and −1), leading to unique three-terminal Weyl complex (one quadratic double-Weyl and two linear single-Weyl) with double surface arcs in SrSi<subscript>2</subscript>. In addition, we apply a uniaxial tensile strain along z-axis to examine the evolution of the three-terminal Weyl complex when the corresponding symmetries are broken. Our work not only provides an ideal candidate for the realization of the quadratic double-Weyl and the corresponding unique surface arc states, but also broadens the understanding of topological Weyl physics. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20573960
- Volume :
- 6
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- NPJ Computational Materials
- Publication Type :
- Academic Journal
- Accession number :
- 144371820
- Full Text :
- https://doi.org/10.1038/s41524-020-00354-y