NIST tracks photon path in a silicon device
U.S. based National Institute of Standards and Technology (NIST) and University of Maryland's Joint Quantum Institute (JQI) have done some research on how photon particles of light flow within a silicon device they have built.
NIST has done this research to help design photon-based logic/computer circuits, so that light can be used as a medium instead of electrons.
"We knew building an analogous system that uses photons would have additional advantages," says NIST physicist Mohammad Hafezi. "Light can carry much more information than electricity, so working with a photon-based system also could help us design computer components that use light."
The NIST team has built an array of tiny, nearly flat silicon rings atop an oxide surface. Beaming photons of the right wavelength at one of the rings makes these photons loop around the ring many times.
But why go through the trouble of making the photons go ring-hopping? Hafezi says the rings encourage the photons to travel only along the edge of the array instead of taking a path through its midsectionójust like electrons experiencing the quantum Hall effect do in a conductor. The secret, he says, lies in the rings' arrangement and its peculiar effect on the photons.
"Our theory showed the topology of the ring array would create the effect we wanted, and our experiment confirms it," Hafezi says. "We now have a robust silicon device that can transport photons at room temperature. We hope it will prove useful for both fundamental studies of physics as well as practical component design."
Author: Srinivasa Reddy N