Alternative pathway technique holds promise for photon based chips

As well as the possibility of leading to more efficient information processors on our desktops, the scientists believe the effort could also offer a way to explore a particularly strange effect of the quantum world known as the quantum hall effect, in which electrons can interfere with themselves as they travel in a magnetic field. While the advent of optical fibers a few decades ago made it possible to send photons across a town or across the ocean, researchers have struggled to employ them as carriers across short distances inside computer chips. This, according to NIST theoretical physicist Jacob Taylor, is due to slight defects in the materials chips are made from. These defects are particularly problematic when they occur in photon delay devices, which slow the photons down to store them briefly until the chip needs the information they contain. "Delay devices are usually constructed from a single row of tiny resonators, so a defect among them can ruin the information in the photon stream," Taylor explained. As such, the researchers set out to create an alternative technique and perceived that using multiple rows of resonators could build alternate pathways into the delay devices, allowing the photons to find their way around defects more easily. The team believes the advance could help overcome obstacles blocking the development of photon based chips, something Taylor notes has long been a dream of computer manufacturers. In terms of further exploring the hall effect, lead researcher Mohammad Hafezi hopes the devices will allow the team to sidestep some of the problems with observing the physics directly and instead allow them to explore them by analogy. The research was undertaken by the Joint Quantum Institute of the National Institute of Standards and Technology and the University of Maryland, together with Harvard University.