The idea to perform data processing with light, without relying on any electronic components, has been around for quite some time. In fact, necessary components such as optical transistors are available. However, up to now they have not gained a lot of attention from computer companies. This could change in the near future as packing densities of electronic devices as well as clock frequencies of electronic computers are about to reach their limits. Optical techniques promise a high bandwidth and low dissipation power, in particular, if only faint light pulses are needed to achieve the effect of switching. The ultimate limit is a gate-pulse that contains one photon only. A team of scientists has now managed to bring this almost utopian task into reality. The scientists succeeded in switching a medium — a cloud of about 200 ultracold atoms — from being transparent to being opaque for light pulses. This “single-photon-switch” could be the first step in the development of a quantum logic gate, an essential component in the field of quantum information processing.
from Physics News — ScienceDaily http://ift.tt/1jfT6Qb