The current in any lightbulb flows due to a difference in voltage, to overcome the electrical resistance. But not in superconductors, where the current doesn’t experience any resistance. Superconductive currents require a phase difference to flow, which so far required energy to create. Scientist from QuTech at Delft University built a so called Phi0 Josephson Junction, that has a phase difference at default. It can therefor function as a tiny battery to store superconducting currents. The scientist published their work on 2 May in Nature Physics.
Their research might help to operate large arrays of superconducting quantum bits, potential candidates to use in a future quantum computer. It is also another step towards the definite proof of Majorana fermions, an elusive particle for which the first signs where seen in QuTech in 2012, that form another potential qubit candidate. The conditions required for a phi0 Josephson Junction are identical to those needed for Majorana’s to appear.