Liquid Light Switch
Liquid Light Switch: Scientists working at the University of Cambridge have used a form of liquid light to create a semiconductor switch that is so small that it not only blurs the distinction between light and electricity, but could also enable the development of much faster and smaller electronic components well into the future. Using a Polariton Bose-Einstein condensate form of “liquid light”, researchers have created a nanoscale switch that could help vastly improve the speed and efficiency of future electronic components. With contemporary methods used to convert between electrical signals and optical ones considered largely inefficient, University of Cambridge researchers believe that it would be better simply to cut out the middleman and mix the two together. In a quest to achieve this, the researchers created a switch using a new state of matter known as a Polariton Bose-Einstein condensate to combine electric and optical signals, while consuming infinitesimally small quantities of energy in the process.
To create a Polariton Bose-Einstein condensate, laser light is first captured between mirrors in a microcavity just a few microns in size. Here the light interacts with thin sections of semiconductor material to produce a half-light, half-matter combination of quasi-particles known as a polariton, which are made up of semiconductor excitons (excited electrons bound to the hole produced by their excitation) and photons. Just like other forms of energy that create strange and interesting amalgams between energy and matter at the nanoscale, such as the newly-discovered topological plexciton, polariton fluid promises to greatly increase electronic efficiency, but it also only tends to work at cryogenic temperatures. As such, the Cavendish Laboratory scientists are researching other types of material that exhibit the same properties at ambient temperatures, in the hope of commercializing the technology and integrating it with existing devices. The researchers say the fact the prototype was based on well-established fabrication technology gives the prototype the potential to be scaled up, which is a key aspect in terms of future mass production potential.