The first thing you learn in electrical engineering is Ohm’s Law, which basically says that toaster and hair dryer wires get hot. To use the first-grade science analogy, just like sticks get hot when you rub them, wires get hot when the moving electrons that make up electricity rub against the metal atoms in the wire. Then in 1911 a Dutch physicist named Heike Onnes discovered superconductivity – get a wire cold enough, the atomic crystaline structure in a wire “smooths out” so the rush of electrons produces no “friction” or waste heat at all. (Hey, you’re ready for physics PhD prelim exams with an explanation like that!) Problem is, Dr. Onnes and those who came after him could only get it to work if super-cold (and expensive) liquid helium was used as the coolant. In 1986, a new category of so-called “high-temperature” superconductors were discovered, but the term was relative – you still needed super-cold (but fairly common and not so expensive) liquid nitrogen to get this type of superconductor to work. Plus, these were ceramics, not metals, so making wire was an exercise in frustration that has hampered technological utilization. Worth a Nobel Prize, though, and made a few scientific careers…
Since then the goal has been to create some kind of superconducting material that needed no coolant at all to work – so called “room temperature” superconductors. The things you could do with such a material boggles the imagination – it would almost be as good as going from the Stone Age to the Metal Age. Now a scientist in South Africa says he’s found such a material – not a metal, not a ceramic, but diamond that’s been treated with oxygen. Results from his experiments have been published in a special issue of Semiconductor Science and Technology (18 S131). “If it is not superconductivity then it must be violating the second law of thermodynamics,” says Johan Prins of the University of Pretoria. However, the rest of the diamond community remains to be convinced. Richard Jackman of University College London, who edited the special issue of the journal in which Prins’ papers appear, describes them as “largely theoretical papers, thought provoking and very controversial – the end conclusions remain open to debate”. Prins is half-way through writing six theoretical papers that will, he claims, fully explain the results and shed new light on the mechanisms underlying high-temperature superconductivity. He has offered to fly his samples to another lab for independent verification but has not yet found any volunteers. Don’t worry, he will – his claim is the stuff of which dreams are made.