Reconstructing Critical Current Density in Josephson Junctions with Phase Non-linearity

TL;DR

This paper identifies limitations of the standard analysis method for Josephson junctions with nonlinear phase distributions and introduces an iterative reconstruction algorithm that improves accuracy by incorporating prior knowledge.

Contribution

The paper presents a novel iterative reconstruction algorithm that overcomes the breakdown of traditional methods in Josephson junctions with phase non-linearity.

Findings

The new method accurately reconstructs critical current density in simulated models.

Experimental validation confirms the effectiveness of the iterative approach.

The approach addresses ambiguity issues in interference pattern analysis.

Abstract

In this Letter, we show that the standard Dynes-Fulton analysis, commonly used to reconstruct the critical current density from interference patterns, breaks down in Josephson junctions with nonlinear phase distributions, leading to non-physical artifacts. To address this, we developed a simple iterative reconstruction algorithm and validated it both numerically and experimentally using a planar Josephson junction model. Unlike conventional approaches based on the logarithmic Hilbert transform, the proposed method allows for incorporating prior knowledge about the system and addresses the fundamental issue of ambiguity in reconstructing the critical current density from interference patterns.