Comparative Study of First and Second Switches with Nearly Identical Switching Current in Bi${}_2$Sr${}_2$Ca${}_{0.85}$Y${}_{0.15}$Cu${}_2$O${}_y$ Intrinsic Josephson Junctions

Abstract

We present a study of the first and second switches (SWs) with nearly identical switching current $I_{\mathrm{SW}}$ in Bi${}_2$Sr${}_2$Ca${}_{0.85}$Y${}_{0.15}$Cu${}_2$O${}_y$ intrinsic Josephson junctions (IJJs). In contrast to early studies where a large difference between $I_{\mathrm{SW}}^{1st}$ and $I_{\mathrm{SW}}^{2nd}$ was observed, a crossover temperature $T_{\mathrm{cr}}$ to the quantum phase escapes for the 2nd SW is strongly reduced $(\sim$2.8~K) and agrees with that for the 1st SW. This confirms that the anomalous enhancement of $T_{\mathrm{cr}}^{2nd}$, commonly observed in the IJJs with $I_{\mathrm{SW}}^{1st}<I_{\mathrm{SW}}^{2nd}$, originates from the phase running state after the 1st SW. Detailed analysis of the microwave-induced escapes strongly suggests that nonlinear bifurcated phenomena possibly occurs in IJJs.

12 pages, 4 figures

References in corpus (4)

• Macroscopic quantum tunneling in a d-wave high-Tc superconductor
• Enhanced Macroscopic Quantum Tunneling in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ Intrinsic Josephson Junction Stacks
• Switching Dynamics of Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ Intrinsic Josephson junctions: Macroscopic Quantum Tunneling and Self-Heating Effect
• Comparative study of macroscopic quantum tunneling in Bi_2Sr_2CaCu_2O_y intrinsic Josephson junctions with different device structures