# $0$-$\pi$ transitions in a Josephson junction of irradiated Weyl semimetal

## TL;DR

This paper proposes an experimental setup using irradiated Weyl semimetals to observe tunable 0-${ extpi}$ transitions in Josephson currents, revealing anisotropic oscillations linked to chiral node separation.

## Contribution

It introduces a novel method to induce and control 0-${ extpi}$ transitions in Weyl semimetal-based Josephson junctions via photon irradiation.

## Key findings

- Josephson current exhibits anisotropic periodic oscillations as a function of chiral node separation.
- Photon irradiation can precisely tune the effective chiral node separation.
- The proposed setup is robust and feasible for experimental realization.

## Abstract

We propose a setup for the experimental realization of unexpected and anisotropic $0$-$\pi$ transitions of the Josephson current, in a junction whose link is made of irradiated Weyl semi-metal (WSM), due to the presence of chiral nodes. We show using a Green's function technique that the Josephson current through a time-reversal symmetric WSM has anisotropic periodic oscillations as a function of $k_0L$, where $k_0$ is the (relevant) separation of the chiral nodes and $L$ is the length of the sample. This is unexpected, for time-reversal symmetric systems, although it has been shown earlier for time-reversal symmetry breaking WSMs. We then show that the effective value of $k_0$ can be tuned with precision by irradiating the sample with photons resulting in $0$-$\pi$ transitions of the critical current. Finally, we discuss the robustness of our setup.