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arXiv · 2212.07404

Dipolar Weyl semimetals

Alexander C. Tyner·Shouvik Sur
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Abstract

In time-reversal symmetry-broken Weyl semimetals, Weyl points act as monopoles and antimonopoles of the Berry curvature, with a monopole-antimonopole pair producing a net zero Berry flux. The two-dimensional (2D) planes that separate a monopole-antimonopole pair of Weyl points carry quantized Berry flux. In this work, we introduce a class of symmetry-protected Weyl semimetals which host monopole-antimonopole pairs of Weyl points that generate a quantized dipolar Berry flux. Consequently, topologically distinct 2D planes coexist in the Brillouin zone, carrying either quantized monopolar or dipolar flux. We construct a topological invariant -- the staggered Chern number -- to measure the quantized dipolar flux and employ it to topologically distinguish between various Weyl points. Finally, through a minimal two-band model, we investigate physical signatures of bulk topology, including surface Fermi arcs, zero-energy hinge states, and response to insertion of a $\pi$-flux vortex.

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Alexander C. Tyner, Shouvik Sur. 2022-12-14. Dipolar Weyl semimetals. https://doi.org/10.1103/physrevb.109.l081101

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