Dynamical Breaking of Charge Neutrality in Intrinsic Josephson Junctions: Common Origin for Microwave Resonant Absorptions and Multiple-branch Structures in the I-V Characterisitcs

TL;DR

This paper shows that dynamical charge neutrality breaking in intrinsic Josephson junctions explains both microwave resonances and multiple-branch structures in I-V curves, supported by a new theoretical model and numerical simulations.

Contribution

It introduces a Lagrangian-based model incorporating dynamical charge neutrality breaking to explain observed phenomena in intrinsic Josephson junctions.

Findings

Existence of longitudinal collective Josephson plasma mode.

Reproduction of I-V branching behaviors through numerical simulations.

Identification of charge neutrality breaking as the common origin.

Abstract

We demonstrate that both microwave resonant absorptions and multiple-branch structures in the I-V characterisitcs observed in intrinsic Josephson junctions (IJJ's) are caused by dynamical breaking of charge neutrality (DBCN) inside the atomic-scale superconducting layer. The Lagranginan for the time-dependent Lawrence-Doniach model incorporating the effect of the DBCN is proposed, and the longitudinal collective Josephson plasma mode is proved to exist based on the Lagrangian. On the other hands, the branching behaviors in the I-V curves are almost completely reproduced by careful numerical simulations for the model equation derived from the Lagragian.