Synopsis: A New Phase for Photonics

A waveguide’s dielectric properties could result in an effective gauge field for photons even though they have no charge.
Synopsis figure

The Aharonov-Bohm effect is one of the standouts in the bestiary of weird quantum phenomena: charged particles that travel in paths around a magnetic field but don’t pass through it nonetheless are influenced by it. The wave functions of these particles acquire a phase shift that can be measured in an interferometer. In essence, though the classical electric and magnetic fields vanish in the particles’ path, they still experience what is known as a gauge potential (the electric and magnetic potentials in electromagnetism). What about neutral particles like photons, which don’t seem to interact with these gauge potentials⎯could they be subject to an Aharonov-Bohm effect?

Kejie Fang and colleagues at Stanford University, California, report in Physical Review Letters their proposal for creating Aharonov-Bohm phase shifts in photons by modulating the properties of an optical material. They study a slab waveguide structure in which the dielectric permittivity is harmonically modulated.

The authors conclude that this creates an effective gauge potential for photons that should be measurable by applying different modulations to two separate regions of the waveguide and looking for optical interference. One possible application of the photonic Aharonov-Bohm effect that Fang et al. suggest would be an optical isolator useful in fiber-optical information processing systems. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

OpticsMaterials ScienceQuantum Physics

Previous Synopsis

Semiconductor Physics

Nanowire Lasing Explained

Read More »

Next Synopsis

Related Articles

Focus: A Tiny Engine Powered by Light and Liquid Physics
Statistical Physics

Focus: A Tiny Engine Powered by Light and Liquid Physics

A micrometer-sized sphere trapped by optical tweezers in a liquid, under the right conditions, orbits rapidly around the laser beam—creating a potential micromixing device. Read More »

Viewpoint: Intense Laser Sheds Light on Radiation Reaction
Plasma Physics

Viewpoint: Intense Laser Sheds Light on Radiation Reaction

Experimentalists have used ultraintense laser light to explore a fundamental problem in quantum electrodynamics: the response of an accelerated electron to the radiation it emits. Read More »

Synopsis: Detecting Energy-Time Entanglement
Quantum Information

Synopsis: Detecting Energy-Time Entanglement

A new detection system directly observes a type of entanglement in which a photon’s energy is correlated with the time its partner is detected.  Read More »

More Articles