Control of magnetic dipole terahertz radiation by cavity-based phase modulation

Area of Science:

• Condensed Matter Physics
• Quantum Optics
• Materials Science

Background:

• Ultrafast spin manipulation is key for terahertz (THz) radiation sources, spintronics, and quantum information processing.
• Performance in these areas is often limited by weak coupling between radiation fields and magnetic dipole oscillations.
• Antiferromagnetic (AFM) materials offer potential but require efficient energy extraction methods.

Purpose of the Study:

• To propose and demonstrate an effective cavity-based phase modulation technique for efficient energy extraction from weak magnetic systems.
• To control magnetic dipole THz radiation generated via nonlinear Raman processes in AFM NiO.
• To investigate the influence of phase modulation on THz radiation dynamics.

Main Methods:

• Utilized an asymmetric coupled Fabry-Pérot (FP) cavity, formed by a NiO slab and a nearby metallic mirror.
• Manipulated the NiO-mirror distance to control the phase relation between magnetic waves and induced magnetization.
• Employed numerical analysis of radiation dynamics to understand the phase modulation effects.

Main Results:

• Demonstrated effective control over THz radiation energy extraction by adjusting the NiO-mirror distance.
• Observed distinct radiation control, confirming the phase modulation's role.
• Numerical analysis validated the experimental findings, highlighting the importance of phase modulation.

Conclusions:

• The proposed cavity-based phase modulation technique offers an effective route for efficient THz radiation generation from weak magnetic systems.
• This method enables precise control over THz radiation output, crucial for advanced spintronic and quantum applications.
• The study highlights the significance of phase modulation in optimizing energy extraction processes in antiferromagnetic materials.