Ultrapure isotope boosts silicon-based quantum computing

BBC : Researchers have developed a method to create very pure samples of silicon-28, whose lack of nuclear spin makes it ideal for a certain type of quantum computation. Purity is paramount, because the presence of other naturally occurring isotopes, such as silicon-29, can shorten the lifetime of electron-based qubits. Obtaining pure silicon-28 has proven a difficult and expensive process. Now the researchers have shown that an analytical chemistry technique—mass spectrometry—common in most laboratories can be used to identify and separate the different silicon isotopes. Although the method can produce only a very small amount of silicon-28, it is enough to work with as long as quantum computing remains in the research phase. Ultrapure silicon-28 is also an ingredient of the Avogadro Project , an international initiative to develop a new, artifact-free standard for the kilogram based on Avogadro’s number.