Colloquium: Quantum interference of clusters and molecules

TL;DR

This paper reviews recent advances in matter wave interferometry with complex molecules and clusters, highlighting experimental techniques, theoretical insights, and future directions for testing quantum superposition at larger scales.

Contribution

It provides a comprehensive overview of different interference methods, discusses experimental and theoretical challenges, and explores prospects for testing quantum mechanics with larger particles.

Findings

Different interference techniques demonstrated with complex molecules.

Interferometry sensitive to internal properties of nanoparticles.

Potential to probe quantum superposition at high mass and complexity.

Abstract

We review recent progress and future prospects of matter wave interferometry with complex organic molecules and inorganic clusters. Three variants of a near-field interference effect, based on diffraction by material nanostructures, at optical phase gratings, and at ionizing laser fields are considered. We discuss the theoretical concepts underlying these experiments and the experimental challenges. This includes optimizing interferometer designs as well as understanding the role of decoherence. The high sensitivity of matter wave interference experiments to external perturbations is demonstrated to be useful for accurately measuring internal properties of delocalized nanoparticles. We conclude by investigating the prospects for probing the quantum superposition principle in the limit of high particle mass and complexity.