A twisted X-ray beam with orbital angular momentum is employed in a theoretical study to probe molecular chirality. A nonlocal response description of the matter-field coupling is adopted to account for the field short wavelength and the structured spatial profile. We use the minimal-coupling Hamiltonian, which implicitly takes into account the multipole contributions to all orders. The combined interactions of the spin and orbital angular momentum of the X-ray beam give rise to circular-helical dichroism signals, which are stronger than ordinary circular dichroism signals, and may serve as a useful tool for the study of molecular chirality in the X-ray regime.
Majed Chergui, Oliviero Cannelli, Giulia Fulvia Mancini, Malte Oppermann, Camila Bacellar Cases Da Silveira, Dominik Kinschel, Christian David, Jérôme Lacour
Hatice Altug, Felix Ulrich Richter, Yasaman Jahani, Rui Lu, Bang Hyun Lee, Ming-Lun Tseng, Longfang Ye