Spontaneous Generation of Magnetic Flux in Superconductors: Testing the Model

The Kibble-Zurek scenario of the generation of topological defects, applied to superconductors, predicts the spontaneous formation of magnetic flux during a rapid quench through T^c. The predicted amount of net flux scales as the 1/8 power of the cooling rate, and as the square root of the circumference of the sample. Our experimental data is broadly consistent with the first prediction, while the second one is yet to be tested. We describe a proposed experiment to test this prediction. In addition, we describe additional observations of spontaneous flux generated through a different mechanism. PACS numbers: 05.70.Ln, 74.40.+k, 11.27.+d.