# Quantum electromagnetic X-waves

## TL;DR

This paper explores the quantum states of electromagnetic X-waves, linking classical solutions to quantum entanglement properties, and discusses their generation, detection, and potential applications in quantum information.

## Contribution

It introduces a novel connection between classical X-waves and quantum states, highlighting entanglement features and proposing methods for their generation and detection.

## Key findings

- Two quantum states correspond to classical X-waves, one entangled and one disentangled.
- Different linear or nonlinear processes can generate these quantum X-waves.
- Potential applications include quantum information processing with Schrödinger-cat states.

## Abstract

We show that two distinct quantum states of the electromagnetic field can be associated to a classical vector X wave or a propagation-invariant solution of Maxwell equations. The difference between the two states is of pure quantum mechanical origin since they are internally entangled and disentangled, respectively and can be generated by different linear or nonlinear processes. Detection and generation of Schr\"odinger-cat states comprising two entangled X-waves and their possible applications are discussed.