Researchers in Hong Kong have discovered superconductivity in carbon nano-tubes in a breakthrough that is expected to trigger new research at physics labs worldwide.
The findings of Professor Sheng Ping and his team at the Hong Kong University of Science and Technology, overturn a long-standing scientific consensus about the behaviour of carbon at low temperatures.
The research team demonstrated through four separate experiments that carbon nano-tubes in a man-made material called zeolite are superconducting at 15 degrees kelvin.
Nano-tubes are important because they are the most hotly-tipped contenders in the race to find an alternative material to silicon, which is predicted to run out within about 20 years, for making computer chips.
Professor Sheng is chair professor and director at the university's William Mong Institute of Nano Science and Technology. He and his team, who developed the smallest carbon nano-tubes in the world in 2000, have pioneered the use of zeolite, which has a molecular structure shaped like a lotus root, to investigate the electrical conductivity of carbon nano-tubes. After hitting on data 10 years ago that suggested the presence of superconductivity in the nano-tubes, they mounted some promising early experiments but found one puzzling result requiring further explanation. Electrical resistance did not drop to zero at the temperature at which superconductivity appeared, as it should have done.
However, the team has now carried out two further tests that corroborated their existing evidence for superconductivity in carbon nano-tubes, while the puzzling aspects have disappeared due to better samples and new techniques.
