Reversibility of superconducting nb weak links driven by the proximity effect in a quantum interference device.
We demonstrate the role of the proximity effect in the thermal hysteresis of superconducting constrictions. From the analysis of successive thermal instabilities in the transport characteristics of micron-size superconducting quantum interference devices with a well-controlled geometry, we obtain a complete picture of the different thermal regimes. These determine whether or not the junctions are hysteretic. Below the superconductor critical temperature, the critical current switches from a classical weak-link behavior to one driven by the proximity effect. The associated small amplitude of the critical current makes it robust with respect to the heat generation by phase slips, leading to a nonhysteretic behavior.
Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Nikhil
N
Kumar
Université Grenoble Alpes, Institut Néel, F-38042 Grenoble, France.|CNRS, Institut Néel, F-38042 Grenoble, France.
T
T
Fournier
Université Grenoble Alpes, Institut Néel, F-38042 Grenoble, France.|CNRS, Institut Néel, F-38042 Grenoble, France.
H
H
Courtois
Université Grenoble Alpes, Institut Néel, F-38042 Grenoble, France.|CNRS, Institut Néel, F-38042 Grenoble, France.
C B
CB
Winkelmann
Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Anjan K
AK
Gupta