# Floquet multi-Weyl points in crossing-nodal-line semimetals

## TL;DR

This paper proposes that crossing-nodal-line semimetals, when driven by circularly polarized light, can host Floquet multi-Weyl points, including double-Weyl points, with potential experimental verification via pump-probe spectroscopy.

## Contribution

It introduces a new mechanism for realizing Floquet multi-Weyl points in crossing-nodal-line semimetals using circularly polarized light.

## Key findings

- Driving crossing nodal lines creates double-Weyl points.
- Monopole charge combination and annihilation are demonstrated.
- Proposals are experimentally verifiable with pump-probe ARPES.

## Abstract

Weyl points with monopole charge $\pm 1$ have been extensively studied, however, real materials of multi-Weyl points, whose monopole charges are higher than $1$, have yet to be found. In this Rapid Communication, we show that nodal-line semimetals with nontrivial line connectivity provide natural platforms for realizing Floquet multi-Weyl points. In particular, we show that driving crossing nodal lines by circularly polarized light generates double-Weyl points. Furthermore, we show that monopole combination and annihilation can be observed in crossing-nodal-line semimetals and nodal-chain semimetals. These proposals can be experimentally verified in pump-probe angle-resolved photoemission spectroscopy.