A New Kind of Quantum Junction
A new type of quantum bit called a “phase-slip qubit,” devised by researchers at the RIKEN Advanced Science Institute and their collaborators, has enabled the world’s first-ever experimental demonstration of coherent quantum phase slip (CQPS). The groundbreaking result sheds light on an elusive phenomenon whose existence — a natural outcome of the hundred-year-old theory of superconductivity — has long been speculated, but never actually observed.
In a paper in Nature, the researchers report on the first direct observation of CQPS in a narrow superconducting wire of indium-oxide (InOx). The wire is inserted into a larger superconducting loop to form a new device called a phase-slip qubit, with the superconducting layer (the thin wire) sandwiched between insulating layers of empty space.