High-harmonic spin-orbit angular momentum generation in crystalline solids preserving multiscale dynamical symmetry

Area of Science:

• Nonlinear optics
• Solid-state physics
• Quantum optics

Background:

• Symmetries govern conservation rules in light-matter interactions, crucial for photon conversion and electron dynamics.
• Anisotropic solids possess rich symmetries, making them suitable for controlling optical structures like spin and orbital angular momentum.
• Understanding these symmetries is key to manipulating light properties.

Purpose of the Study:

• To demonstrate structured high-harmonic generation (HHG) driven by the anisotropic symmetry of solids.
• To explore the generation of multiple orbital angular momentum (OAM) states in HHG.
• To investigate the role of dynamical symmetry, specifically from light's spin-orbit interaction, in controlling HHG.

Main Methods:

• Utilizing anisotropic solids with specific symmetries.
• Strategically preserving a dynamical symmetry arising from the spin-orbit interaction of light.
• Experimental generation and analysis of high-order harmonics.

Main Results:

• Structured high-harmonic generation was successfully linked to the anisotropic symmetry of the solid.
• Multiple orbital angular momentum states were generated in high-order harmonics by preserving dynamical symmetry.
• Experimental results confirmed the conservation of total angular momentum of light in the extreme nonlinear regime.

Conclusions:

• The observed phenomena originate from a dynamical symmetry, evidenced by total angular momentum conservation.
• This study deepens the understanding of multiscale nonlinear optical phenomena.
• Provides a framework for controlling structured light using electronic structures, potentially via Floquet engineering.