Current redistribution effects in superconductors

by Prof. Ruggero Vaglio (Università Degli Studi Di Napoli Federico II)

Wednesday 27 May 2026, 11:00 → 13:00 Europe/Rome

M. B. Ceolin meeting room

Since early times in the story of superconductivity and nowadays, anomalous peaks (or dips) close to the critical temperature Tc have been occasionally observed in measuring transport properties of superconductors. This can occur pretty often in resistivity and critical current measurements of thin films or tapes, but can also occur in other type of measurements and, in particular, in rf superconducting cavity frequency or impedance measurement.
These spectacular peaks have been, by time, interpreted in different ways, often in terms of fancy theoretical models. However, it has been now largely recognized that at least the anomalous peaks in thin films resistance versus temperature measurements and in tapes critical current measurements are due to “trivial” current redistribution effects related to minor inhomogeneities of the measured samples.
In this lecture we will review this topic and give evidence that current redistribution effects can also be at the origin of the anomalous peaks (or dips) observed in rf superconducting cavity frequency and impedance measurements.