Discovered over 100 years ago, it still works. Certain materials loose resistance when cooled below their critical temperature. One of these, a niobium-titanium-nitride alloy, is now available in Pittsburgh. It is an important material for Majorana fermion research, but also for single photon detectors, superconducting qubits… Almost on the first try we got the critical superconducting temperature of 11K, which is not the highest for this material, but will work for us in the short term. The film was produced in the AJA sputtering machine from a couple of posts below.
(Resistance vs. temperature plot in the ‘as is’ form)