Theory of entanglement and measurement in high harmonic generation

TL;DR

This paper introduces a quantum information framework for high harmonic generation, enabling new quantum state engineering protocols and measurement techniques in intense laser-matter interactions.

Contribution

It provides a quantum mechanical description of measurement protocols in high harmonic generation, linking quantum information theory with laser-driven processes for the first time.

Findings

Quantum measurement protocols for high harmonic generation are developed.

Positive operator-valued measures for optical field modes are derived.

Generation of high-dimensional entangled states and non-classical superpositions is demonstrated.

Abstract

Quantum information science and intense laser matter interaction are two apparently unrelated fields. Here, we introduce the notion of quantum information theory to intense laser driven processes by providing the quantum mechanical description of measurement protocols for high harmonic generation in atoms. This allows to conceive new protocols for quantum state engineering of light. We explicitly evaluate conditioning experiments on individual optical field modes, and provide the corresponding quantum operation for coherent states. The associated positive operator-valued measures are obtained, and give rise to the quantum theory of measurement for the generation of high dimensional entangled states, and coherent state superposition with controllable non-classical features on the attosecond timescale. This establish the use of intense laser driven processes as a novel quantum technology platform for quantum information processing.