paper

The discovery, disappearance and re-emergence of radiation-stimulated superconductivity

arXiv:1911.02793 · doi:10.1016/j.aop.2020.168104

Abstract

We trace the historical fate of experiment and theory of microwave-stimulated superconductivity as originally reported for constriction-type superconducting weak links. It is shown that the observed effect disappeared by improving weak links to obtain the desired Josephson-properties. Separate experiments were carried out to evaluate the validity of the proposed theory of Eliash'berg for in superconducting films in a microwave field, without reaching a full quantitatively reliable measurement of the stimulated energy gap in a microwave-field, but convincing enough to understand the earlier deviations from the Josephson-effect. Over the same time-period microwave-stimulated superconductivity continued to be present in superconductor-normal metal-superconductor Josephson weak links. This experimental body of work was left unexplained for several decades and could only be understood properly after the microscopic theory of the proximity-effect had matured enough, including its non-equilibrium aspects. It implies that the increase in critical current in weak-link Josephson-junctions is due to an rather than to an as proposed by Eliash'berg. The complex interplay between proximity-effect and the occupation of states continuous to be, in a variety of ways, at the core of the ongoing research on hybrid Josephson-junctions. The subject of radiation-enhanced superconductivity has re-emerged in the study of the power-dependence of superconducting microwave resonators, but also in the light-induced emergence of superconductivity in complex materials.

Comments welcome. Submitted to the Annals of Physics special issue dedicated to the 90th birthday of Eliash'berg

References in corpus (3)

Cited by in corpus (9)