A team of researchers at the University of Tokyo in Japan has discovered a material that can be used to create cheaper, much larger super discs that can store 5,000 times the capacity of today's average DVD. The leader of the research team, Shin-ichi Ohkoshi, a chemistry professor at the University of Tokyo, said on the 24th that the material, which is normally a black metal state that can conduct electricity, turns into a brown semiconductor when it is clicked by light. This is a new type of transparent titanium oxide that is exposed to light at room temperature and can be arbitrarily converted between metals and semiconductors, thus producing the function of storing data.