Voltage-biased I-V characteristics in the multi-Josephson junction model of high T$_c$ superconductor

TL;DR

This paper explores the complex voltage-current behavior in multi-Josephson junctions of high T$_c$ superconductors, revealing characteristic regions and oscillations caused by inter-layer couplings, which could confirm the underlying coupling mechanisms.

Contribution

It introduces a detailed analysis of I-V characteristics in multi-Josephson junctions, highlighting the effects of inter-layer coupling on the nonlinear behavior.

Findings

Identification of three characteristic regions in I-V curves

Discovery of chaotic behavior in intermediate voltage range

Observation of multi-branch structure at high voltages

Abstract

By use of the multi-Josephson junction model, we investigate voltage-biased I-V characteristics. Differently from the case of the single junction, I-V characteristics show a complicated behavior due to inter-layer couplings among superconducting phase differences mediated by the charging effect. We show that there exist three characteristic regions, which are identified by jumps and cusps in the I-V curve. In the low voltage region, the total current is periodic with trigonometric functional increases and rapid drops. Then a kind of chaotic region is followed. Above certain voltage, the total current behaves with a simple harmonic oscillation and the I-V characteristics form a multi-branch structure as in the current-biased case. The above behavior is the result of the inter-layer coupling, and may be used to confirm the inter-layer coupling mechanism of the formation of hysteresis branches.