Nanophotonics for pair production

TL;DR

This paper proposes using nanostructured materials and intense optical near fields to enhance electron-positron pair production from high-energy photons, opening new possibilities in particle physics and nanophotonics.

Contribution

It introduces a novel method combining nanophotonics and high-energy photons to significantly increase pair-production efficiency.

Findings

Near-threshold gamma-ray interaction with polaritons increases pair-production cross sections.

Nanostructured materials enable tunable pulsed positron generation.

The approach surpasses free-space photon pair production rates.

Abstract

The transformation of electromagnetic energy into matter represents a fascinating prediction of relativistic quantum electrodynamics that is paradigmatically exemplified by the creation of electron-positron pairs out of light. However, this phenomenon has a very low probability, so positron sources rely instead on beta decay, which demands elaborate monochromatization and trapping schemes to achieve high-quality beams. Here, we propose to use intense, strongly confined optical near fields supported by a nanostructured material in combination with high-energy photons to create electron-positron pairs. Specifically, we show that the interaction between near-threshold gamma-rays and polaritons yields higher pair-production cross sections, largely exceeding those associated with free-space photons. Our work opens an unexplored avenue toward generating tunable pulsed positrons at the intersection between particle physics and nanophotonics.