University College London’s London Centre for Nanotechnology is looking into the magneto-optical properties of materials including organometallic films and rare-earth fluoride crystals. The aim is to find a means of storing quantum information, which would be an essential part of creating a quantum computer. Certain materials cause the polarization properties of light to change. The Magneto-Optical Kerr Effect on reflected light and the Faraday effect on transmitted light have been used in information storage devices such as magneto-optical disks. Nanotech opens the possibility of exploiting these effects in unpaired electronic spins.