Single-particle incoherent diffractive imaging and amplified spontaneous emission in copper nanocubes

TL;DR

This paper demonstrates element-specific incoherent diffractive imaging of single copper nanocubes using X-ray fluorescence correlations, achieving high resolution and revealing limits imposed by amplified spontaneous emission at high fluences.

Contribution

It extends incoherent diffractive imaging to single particles and high fluence regimes, combining fluorescence correlation with diffraction classification.

Findings

Achieved 20 nm resolution in imaging 88 nm copper nanocubes.

IDI visibility sharply decreases above 100 J/cm^2 fluence.

Revealed fundamental limits for high-fluence nanoimaging.

Abstract

We demonstrate element-specific incoherent diffractive imaging (IDI) of single copper nanocubes using intensity correlations of K$\alpha$ fluorescence at a hard X-ray free-electron laser. Combining single particle diffraction classification with IDI, we retrieve the form factor of 88 nm cubes with 20 nm resolution, extending IDI to the destructive single-particle regime with a large gain in resolution. IDI visibility drops sharply above a fluence of $10^2$ J/cm$^2$, consistent with the assumption of amplified spontaneous emission. Our results reveal fundamental limits for high-fluence nanoimaging towards future single-particle X-ray imaging.