Nonlinear magneto-optical injection currents in multi-Weyl semimetals

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Optics

Background:

• Multi-Weyl semimetals exhibit unique topological properties with potential applications in next-generation electronics.
• Nonlinear optical phenomena are crucial for understanding charge dynamics in novel materials.
• Magneto-optical effects provide insights into electronic band structures under magnetic fields.

Purpose of the Study:

• To develop a microscopic theory for nonlinear magneto-optical injection currents in multi-Weyl semimetals.
• To investigate the influence of monopole charge and magnetic fields on these currents.
• To establish a direct link between transport phenomena and topological properties.

Main Methods:

• Formulation of a Kubo-type nonlinear response theory in the Landau-level basis.
• Derivation of the second-order conductivity tensor using a tilted multi-Weyl Hamiltonian.
• Analysis of optical transitions, including chiral-chiral, chiral-bulk, and bulk-bulk contributions.

Main Results:

• Identification of distinct contributions to injection currents with characteristic monopole-charge scaling.
• Observation of sharp resonant structures governed by Landau-level selection rules and tilt-induced asymmetry.
• Emergence of universal frequency thresholds and experimental signatures of higher-order Weyl topology in the untilted limit.

Conclusions:

• Nonlinear magneto-optical injection currents serve as a direct transport probe.
• The theory elucidates the role of chiral Landau levels and multi-Weyl topological charge.
• This work provides a framework for exploring topological properties in semimetals.