Quantum Imaging with Incoherently Scattered Light from a Free-Electron Laser

TL;DR

This paper demonstrates that higher-order intensity correlations of incoherently scattered x-rays from free-electron lasers can be used to achieve high-resolution imaging of two-dimensional objects, surpassing traditional limits and enabling new structural analysis methods.

Contribution

It introduces a novel imaging technique utilizing higher-order coherence in incoherent x-ray scattering, extending Hanbury Brown and Twiss intensity correlation methods for structure determination.

Findings

Achieved spatial resolution near or below the Abbe limit.

Demonstrated imaging using incoherent scattering processes like Compton scattering.

Extended intensity correlation techniques beyond second-order for structural analysis.

Abstract

The advent of accelerator-driven free-electron lasers (FEL) has opened new avenues for high-resolution structure determination via diffraction methods that go far beyond conventional x-ray crystallography methods. These techniques rely on coherent scattering processes that require the maintenance of first-order coherence of the radiation field throughout the imaging procedure. Here we show that higher-order degrees of coherence, displayed in the intensity correlations of incoherently scattered x-rays from an FEL, can be used to image two-dimensional objects with a spatial resolution close to or even below the Abbe limit. This constitutes a new approach towards structure determination based on incoherent processes, including Compton scattering, fluorescence emission or wavefront distortions, generally considered detrimental for imaging applications. Our method is an extension of the landmark intensity correlation measurements of Hanbury Brown and Twiss to higher than second-order paving the way towards determination of structure and dynamics of matter in regimes where coherent imaging methods have intrinsic limitations.