Enantioselective orientation of chiral molecules induced by terahertz pulses with twisted polarization

Chirality and chiral molecules are key elements in modern chemical and biochemical industries. Individual addressing, and the eventual separation of chiral enantiomers has been and still is an important elusive task in molecular physics and chemistry, and a variety of methods has been introduced over the years to achieve this goal. Here, we theoretically demonstrate that a pair of cross-polarized THz pulses interacting with chiral molecules through their permanent dipole moments induces an enantioselective orientation of these molecules. This orientation persists for a long time, exceeding the duration of the THz pulses by several orders of magnitude, and its dependency on temperature and pulses' parameters is investigated. The persistent orientation may enhance the deflection of the molecules in inhomogeneous electromagnetic fields, potentially leading to viable separation techniques.