Multichannel High-Order Harmonic Generation from Fractal Bands in Fibonacci Quasicrystals

Area of Science:

• Solid-state physics
• Attosecond science
• Quantum optics

Background:

• High-order harmonic generation (HHG) in solids is efficient due to high density.
• Crystal transition laws limit HHG channels, hindering efficiency.
• Quasicrystals offer potential for multichannel HHG due to fractal band structures.

Purpose of the Study:

• Investigate high-order harmonic generation (HHG) in Fibonacci quasicrystals (FQ).
• Analyze electron dynamics on the attosecond timescale in FQ.
• Explore quasicrystals as a novel platform for HHG.

Main Methods:

• First-time simulation of HHG in Fibonacci quasicrystals.
• Analysis of electron trajectories using the acceleration theorem.
• Investigation of electron dynamics and excitation channels.

Main Results:

• The acceleration theorem is approximately applicable in FQ, aiding trajectory analysis.
• Fractal bands in FQ enable more excitation channels, unlike crystals.
• Broken symmetry in FQ leads to increased electron backscattering.
• FQ exhibits multichannel HHG with higher yield and broader spectral range than crystals.

Conclusions:

• Simulations demonstrate the potential of quasicrystals for enhanced HHG.
• FQ offers a promising route to understanding and controlling HHG.
• This work suggests quasicrystals could enable novel, compact attosecond light sources.