Superfast` quantum computers come close to reality

Washington: A new breakthrough by researchers could help make the dream of quantum computers come true. One atom equals one bit and presently, a compound of several million atoms is needed to stabilize a magnetic bit in a way that hard disk data are secure for several years. "Often, a single atom fixed to a substrate is so sensitive that its magnetic orientation is stable for fractions of a microsecond (200 nanoseconds) only," Wulf Wulfhekel from Karlsruhe Institute of Technology (KIT) explained. Together with colleagues from Halle, he has now succeeded in extending this period by a factor of about a billion to several minutes. "This does not only open up the possibility of designing more compact computer memories, but could also be the basis for the setup of quantum computers," Wulfhekel said.

In their experiment, the researchers placed a single holmium atom onto a platinum substrate. At temperatures close to absolute zero, i.e. at about 1 degree Kelvin, they measured the magnetic orientation of the atom using the fine tip of a scanning tunneling microscope. Wulfhekel emphasized that the magnetic spin changed after about 10 minutes only. Hence, the magnetic spin of the system is stable for a period that is about a billion times longer than that of comparable atomic systems. The study is published in Nature magazine.