Surface to bulk Fermi arcs via Weyl nodes as topological defects
Kun Woo Kim1, Woo-Ram Lee1,2, Yong Baek Kim1,3
1School of Physics, Korea Institute for Advanced Study, Seoul 02455, Korea.
Nature Communications
|November 16, 2016
Summary
The connectivity of surface Fermi arcs in Weyl semimetals is determined by the Zak phase. This topological property also predicts the existence of bulk Fermi arcs, crucial for conserving Weyl fermion number under electric fields.
Area of Science:
- Condensed matter physics
- Materials science
- Topological materials
Background:
- Weyl semimetals are characterized by surface Fermi arcs.
- The connectivity of these arcs with multiple Weyl nodes remains an open question.
Purpose of the Study:
- Investigate the factors determining surface Fermi arc connectivity in Weyl semimetals.
- Explore the role of the Zak phase in their topological structure.
- Identify novel topological phenomena in Weyl semimetals.
Main Methods:
- Calculated the Zak phase integrated along the normal-to-surface direction.
- Analyzed the winding of the Zak phase around projected Weyl nodes.
- Investigated topological defects in Wannier-Stark ladders under electric fields.
- Employed numerical simulations to support theoretical findings.
Main Results:
- Surface Fermi arc locations are primarily dictated by the Zak phase condition.
- The Zak phase reveals the bulk topological structure of Weyl semimetals.
- Winding of the Zak phase acts as a topological defect in Wannier-Stark ladders.
- Discovered bulk Fermi arcs, open-line segments in bulk spectra, linked to surface arcs.
Conclusions:
- The Zak phase is a key determinant of surface Fermi arc connectivity.
- Bulk Fermi arcs are predicted to coexist with surface arcs to conserve Weyl fermion number.
- This work provides new insights into the topological properties and electronic behavior of Weyl semimetals.
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