Josephson radiation patterns in underdamped topological Josephson junctions

TL;DR

This paper investigates the Josephson radiation emitted by underdamped topological Josephson junctions, revealing oscillatory patterns linked to Majorana zero modes, with analytical and numerical analysis confirming Bessel function descriptions.

Contribution

It provides the first analytical and numerical characterization of Josephson radiation patterns induced by Majorana modes in underdamped topological junctions.

Findings

Oscillatory radiation patterns are induced by Majorana two-level systems.

Bessel functions accurately describe the radiation spectra.

Patterns are robust across various junction parameters.

Abstract

Josephson radiation is a useful signature for detecting Majorana zero modes in topological superconductors. We study the Josephson radiation of the underdamped topological Josephson junction within the quantum resistively and capacitively shunted junction model. We show that the quantum dynamics of the Majorana two-level system induce oscillatory patterns in the Josephson emission spectra. With the Floquet method, we obtain analytical results for these oscillatory patterns and find that they are well described by Bessel functions. We perform numerical simulations to verify the analytical results and demonstrate that these Bessel radiation patterns exist for a wide range of junction parameters.