The critical current of disordered superconductors near 0 K

Abstract

An increasing current through a superconductor can result in a discontinuous increase in the differential resistance at the critical current. This critical current is typically associated either with breaking of Cooper-pairs or with the onset of collective motion of vortices. Here we measure the current-voltage characteristics of superconducting films at low temperatures and high magnetic fields. Using heat-balance considerations we demonstrate that the current-voltage characteristics are well explained by electron overheating enhanced by the thermal decoupling of the electrons from the host phonons. By solving the heat-balance equation we are able to accurately predict the critical currents in a variety of experimental conditions. The heat-balance approach is universal and applies to diverse situations from critical currents to climate change. One disadvantage of the universality of this approach is its insensitivity to the details of the system, which limits our ability to draw conclusions regarding the initial departure from equilibrium.

Resistive transition of hydrogen-rich superconductors

“…phonons). However, for materials where the observed T c does not solely depend on the electron-phonon interaction (in particular, in cuprates [51,53,54], pnictides [75][76][77] and nickelates [78,79]), but instead on the thermodynamic fluctuations [58,[80][81][82][83], the presence of pseudogap [84,85], structural disorder [86][87][88][89], system dimensionality [90][91][92][93][94] or other mechanisms [95][96][97][98] for charge carrier wave function distortions, our equations (11) and (12) might not be a good fitting tool (however, it does not necessarily mean that in some cases these equations will still be a good fitting tool). Based on all the above, alternative R(T, B) models may be developed for other types of materials.…”

Hysteresis and jumps in the I-V curves of disordered two-dimensional materials

“…Since this is usually uncontrolled in experiments, it may explain why some samples show hysteresis and jumps, while others, nomi-nally with the same parameters, do not (see, e.g. [47]). Another possible source of slow dynamics may be twolevel systems, which have already been observed [48,49] in similar disordered SC films.…”