Switching Dynamics of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ Intrinsic Josephson junctions: Macroscopic Quantum Tunneling and Self-Heating Effect

TL;DR

This study investigates the switching behavior of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+eta}$ intrinsic Josephson junctions, revealing macroscopic quantum tunneling at low temperatures and significant self-heating effects influencing second switching events.

Contribution

It provides new insights into the switching mechanisms of IJJs, highlighting the roles of quantum tunneling and self-heating effects in their dynamics.

Findings

First switching follows macroscopic quantum tunneling and thermal activation.

Second switching is dominated by self-heating, increasing effective temperature.

Saturation of switching distribution occurs at higher temperatures for second switching.

Abstract

The switching dynamics of current-biased Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ intrinsic Josephson junctions (IJJs) was studied to clarify the effect of d-wave superconductivity and the stack structure on the switching properties. High quality IJJs were fabricated, and then the temperature dependence of the switching probability distribution was measured for the first and second switchings. Although the standard deviation of the distribution detected for both switchings showed similar saturation characteristics with decreasing temperature, the temperature at saturation was about 13 times higher for the second switching than for the first switching. The properties of the first switching can be explained in terms of a conventional underdamped JJ, that is, macroscopic quantum tunneling below the crossover temperature, and thermal activation with quality factor of 70$\pm$20 above the crossover temperature. In contrast, the relatively higher effective temperature for the second switching evaluated from the switching probability distribution suggests a dominant thermal activation process under the influence of the self-heating effect even at sufficiently low temperature.