Using abrupt changes in magnetic susceptibility within type-II superconductors to explore global decoherence phenomena

A phenomenon of a periodic staircase of macroscopic jumps in the admitted magnetic field has been observed, as the magnitude of an externally applied magnetic field is smoothly increased or decreased upon a superconducting (SC) loop of type-II niobium-titanium wire that is coated with a non-SC layer of copper. Large temperature spikes were observed to occur simultaneously with the jumps, suggesting brief transitions to the normal state, caused by en masse motions of Abrikosov vortices. An experiment that exploits this phenomenon to explore the global decoherence of a large SC system will be discussed, and preliminary data will be presented. Although further experimentation is required to determine the actual decoherence rate across the SC system, multiple classical processes are ruled out, suggesting that jumps in magnetic flux are fully quantum mechanical processes that may correspond to large group velocities within the global Cooper pair wavefunction.