Hexagonally warped exceptional physics in multi-Weyl semimetals

Abstract

Hexagonal warping (HW) in three-dimensional topological insulators is, by now, well-known. We show that non-Hermitian (NH) loss/gain can generate an exceptional HW effect in double Weyl-semimetals (DWSM). This unique feature of DWSMs has distinctive effects on Fermi surface topology. Importantly, in the presence of such a $k^3$ spin orbit coupling mimicking term, the symmetry associated with the DWSMs is changed, leading to four exceptional points, among which two are degenerate. Introducing a driving field removes this degeneracy. The combined action of the NH warping and driving parameters leads to notable effects, including merging and tuning of exceptional points. We analyze the topological nature of the generated exceptional contours by evaluating several topological invariants, such as winding number, vorticity, and NH Berry curvature. We hope that our theoretical results would initiate possible experiments exploring NH HW effects.

7 pages, 5 figures

References in corpus (11)

• Photovoltaic Hall effect in graphene
• Topological Semimetals
• Weyl Exceptional Rings in a Three-Dimensional Dissipative Cold Atomic Gas
• New topological invariants in non-Hermitian systems
• Microscopic theory for the light-induced anomalous Hall effect in graphene
• Flat Band in Disorder Driven Non-Hermitian Weyl Semimetals
• Spectral photonic lattices with complex long-range coupling
• Tunable point nodes from line node semimetals via application of light
• Photovoltaic anomalous Hall effect in line-node semimetals
• Floquet dynamics in two-dimensional semi-Dirac semimetals and three-dimensional Dirac semimetals
• Floquet dynamics in multi-Weyl semimetals

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• Generalized bulk-boundary correspondence in periodically driven non-Hermitian systems
• Non-Hermiticity induced Exceptional Points and Skin Effect in the Dice-Haldane Model
• Exceptional points as signatures of dynamical magnetic phase transitions
• Entanglement phase transitions in non-Hermitian Floquet systems
• Phase transition from Weyl to self-linked semimetal using bi-circular laser
• Hexagonal Warping Control of Exceptional Points in Topological Insulator--Ferromagnetic Heterojunctions
• $q$th-root non-Hermitian Floquet topological insulators