X-ray diffraction from chiral molecules with twisted beams

TL;DR

This paper theoretically explores how twisted x-ray beams interact with chiral molecules, revealing that measurable dichroic signals depend on molecular orientation and specific beam and sample conditions.

Contribution

It demonstrates that dichroic signals from twisted x-ray diffraction are only observable when molecules are oriented, clarifying conditions for experimental detection.

Findings

No dichroic signal from randomly oriented molecules.

Dichroic response appears with molecular orientation.

Conditions identified for measurable dichroic scattering.

Abstract

Structured x-rays carrying an orbital angular momentum break spatial inversion symmetry and have been proposed as a means to probe chirality. We theoretically investigate twisted non-resonant x-ray diffraction from chiral molecules and demonstrate that no dichroic signal can arise from randomly oriented molecules, irrespective of the beam spatial profile. However, a dichroic response is found to emerge if the molecule is oriented. Our results establish the beam and sample conditions for which a measurable dichroic scattering signal survives axial and focal averaging.