Radiation emission due to fluxon scattering on inhomogeneity in large two-dimensional Josephson junction

TL;DR

This study analyzes how fluxons in large two-dimensional Josephson junctions emit radiation when interacting with finite-area inhomogeneities, revealing maxima in emitted energy related to impurity geometry.

Contribution

It provides an exact calculation of emitted wave spectral density for specific inhomogeneity shapes and explores the energy-velocity relationship, extending previous point impurity and 1D results.

Findings

Total emitted energy shows at least one maximum as a function of fluxon velocity.

The shape and size of inhomogeneities significantly affect emission maxima.

Connection established between 2D inhomogeneity effects and limiting cases like point impurities.

Abstract

Interaction of a fluxon in the two-dimensional large Josephson junction with the finite area inhomogeneity is studied within the sine-Gordon theory. The spectral density of the emitted plane waves is computed exactly for the rectangular and rhombic inhomogeneities. Total emitted energy as a function of the fluxon velocity exhibits at least one local maximum. Connection to the previously studied limiting cases including the point impurity and the one-dimensional limit has been performed. An important feature o f the emitted energy as a function of the fluxon velocity is a clear maximum (or maxima). The dependence of these maxima on the geometric properties of the impurity has been studied in detail.