Photon Hall Pinwheel Radiation of Angular Momentum by a Diffusing Magneto-Optical Medium

Area of Science:

• Optics and Photonics
• Condensed Matter Physics
• Magneto-optics

Background:

• Angular momentum transfer between light and matter is crucial for understanding light-matter interactions.
• Magneto-optical materials exhibit unique responses to magnetic fields and light.
• The photon Hall effect describes the transverse deflection of photons in a medium.

Purpose of the Study:

• To investigate a novel optical effect involving angular momentum exchange between light and magneto-optical matter.
• To characterize the influence of a homogeneous magnetic field on light propagation within an agglomerate of scatterers.
• To quantify the induced torque resulting from the interaction.

Main Methods:

• Utilizing an optically thick, spherical agglomerate of magneto-optical scatterers.
• Employing a coherent, unpolarized central light source.
• Analyzing the spiraling Poynting vector induced by the photon Hall effect.

Main Results:

• Demonstrated a new optical effect enabling angular momentum exchange between light and matter.
• Observed the photon Hall effect inducing a spiraling Poynting vector both inside and outside the medium.
• Measured an induced torque proportional to light injection power and the photon Hall angle.

Conclusions:

• The study reveals a new mechanism for light-matter angular momentum transfer.
• The photon Hall effect plays a key role in this interaction, leading to observable torques.
• This work opens avenues for controlling angular momentum in optical systems using magneto-optical materials.