Paper: Phys. Rev. Lett.


The Arndt Group published a new article on "Conformer Selection by Matter-Wave Interference" in Physical Review Letters

We establish that matter-wave diffraction at near-resonant ultraviolet optical gratings can be used to spatially separate individual conformers of complex molecules. Our calculations show that the conformational purity of the prepared beam can be close to 100% and that all molecules remain in their electronic ground state. The proposed technique is independent of the dipole moment and the spin of the molecule and thus paves the way for structure-sensitive experiments with hydrocarbons and biomolecules, such as neurotransmitters and hormones, which have evaded conformer-pure isolation so far.

Read more: here.

Setup for the conformer-specific diffraction of molecules. After the first slit skimmer, the adiabatically expanded molecular beam is further reduced in width by the source skimmer (1). Here, the transverse coherence of the molecular beam is prepared to illuminate several antinodes of the standing light wave (2). Matter-wave interference at the optical grating is determined by the dispersive and absorptive interaction between the molecule and the spatially periodic laser field. The resulting interference pattern (3) is spatially filtered by two movable slits to isolate the relevant diffraction peaks. This results in a pure beam of the desired conformer in the science region (4). The molecular beam is collimated by the skimmer S3 to 20  μrad to prevent the diffraction orders from overlapping.