MUNICH, Germany Researchers at Forschungszentrum Rossendorf (Dresden, Germany) say they have succeeded in making superconducting germanium crystals. The achievement could be a step towards faster semiconductors.
The researcher team led by Thomas Herrmannsdörfer doped germanium crystals with an extremely high concentration of impurity atoms: They added six gallium atoms for every 100 germanium atoms. Since this high concentration of impurity atoms led to a strong distortion of the crystal structure, the lattice then had to be repaired by strong light flashes. The 'reparied' crystal exposed characteristics of superconductivity such as a very high critical magnetic field, the researchers write in a press release.
While the superconductivity effect was only verifiable at a very low temperature of only 0.5 K, it was the first time ever germanium has been made superconductive. Similar experiments with silicon had been successfully by a French research team two years ago, but germanium recently had attracted the interest of scientists in the quest to find ways to produce faster chips.
The superconducting germanium is far from being of use for practical purposes, admitted research team member Viton Heera. "But it is possible that we can rise the superconductivity temperature", Heera said. In this case, it perhaps would be possible to build helium-cooled germanium gates with ultra-short switching times.
Practical consequences for semiconductor manufacturing, however are not to be expected in the near future. "This is basic research," Heera said. "We are not even close to an application."