Entanglement and non-classical states of light in a strong-laser driven solid-state system

TL;DR

This paper demonstrates the generation of entangled non-classical light states in a solid-state system driven by strong lasers, leveraging high-order harmonic generation and measurement-based conditioning to enhance quantum features.

Contribution

It introduces a novel method for creating entangled non-classical light in solid-state systems using high-order harmonic generation and measurement conditioning.

Findings

Entanglement between electrons and light is generated in solid-state systems.

Non-classical states of light are characterized and confirmed.

Conditioning operations enhance quantum features in the emitted light.

Abstract

The development of sources delivering non-classical states of light is one of the main needs for applications of optical quantum information science. Here, we demonstrate the generation of non-classical states of light using strong-laser fields driving a solid-state system, by using the process of high-order harmonic generation, where an electron tunnels out of the parent site and, later on, recombines on it emitting high-order harmonic radiation, at the expense of affecting the driving laser field. Since in solid-state systems the recombination of the electron can be delocalized along the material, the final state of the electron determines how the electromagnetic field gets affected because of the laser-matter interaction, leading to the generation of entanglement between the electron and the field. These features can be enhanced by applying conditioning operations, i.e., quantum operations based on the measurement of high-harmonic radiation. We study non-classical features present in the final quantum optical state, and characterize the amount of entanglement between the light and the electrons in the solid. The work sets the foundation for the development of compact solid-state-based non-classical light sources using strong-field physics.