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arXiv:1909.06101 · Journal of the Physical Society of Japan

Comparative Study of First and Second Switches with Nearly Identical Switching Current in Bi2Sr2Ca0.85Y0.15Cu2Oy Intrinsic Josephson Junctions

Ayami Yamaguchi, Haruka Ohnuma, Yuji Watabe, Shumpei Umegai, Kazutaka Hosaka, Haruhisa Kitano

Published Sep 26, 2019• 3 citations
arXivHTMLPDF

Abstract

We present a study of the first and second switches (SWs) with nearly identical switching current $I_{\rm SW}$ 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 $I_{\rm SW}^{\rm 1st}$ and $I_{\rm SW}^{\rm 2nd}$ was observed, a crossover temperature $T_{\rm cr}$ 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 $T_{\rm cr}^{\rm 2nd}$, commonly observed in the IJJs with $I_{\rm SW}^{\rm 1st} < I_{\rm SW}^{\rm 2nd}$, 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.

DOI
10.7566/jpsj.88.103704

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