Using Abrupt Changes in Magnetic Susceptibility within Type-II Superconductors to Explore Global Decoherence Phenomena

TL;DR

This paper investigates abrupt magnetic flux jumps in type-II superconductors coated with copper, linking them to quantum mechanical vortex motions and exploring their implications for understanding global decoherence in superconducting systems.

Contribution

It introduces a novel experimental approach to study global decoherence phenomena using magnetic flux jumps in superconductors, suggesting a quantum mechanical origin for these events.

Findings

Observation of periodic magnetic flux jumps in superconductors

Correlation of flux jumps with temperature spikes and vortex motions

Indication that flux jumps are quantum mechanical in nature

Abstract

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 which is coated with a non-superconducting 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 superconducting system will be discussed, and preliminary data will be presented. Though further experimentation is required to determine the actual decoherence rate across the superconducting system, multiple classical processes are ruled out, suggesting that jumps in magnetic flux are fully quantum mechanical processes which may correspond to large group velocities within the global Cooper pair wavefunction.