FAST TRACK COMMUNICATION Laser-induced conical intersections in molecular optical lattices

Conical intersections of potential energy surfaces widely appear in molecules which consist of more than two atoms. No conical intersections exist in the case of free diatomic molecules. We show here that diatomic molecules interacting with standing laser waves produce periodic arrays of conical intersections. At these laser-induced intersections the non-adiabatic effects are infinitely strong. The translational and rovibrational molecular motions become strongly coupled to each other and energy exchange between the various degrees of freedom influences the dynamics of the system. As an illustrative example, an effect of the laser-induced conical intersections on trapping of ultracold diatomic molecules by light is discussed. (Some figures in this article are in colour only in the electronic version) Conical intersections (CIs) between electronic potential energy surfaces are ubiquitous in polyatomic molecular systems and play a crucial role in various processes, for reviews see e.g. [1–3]. For nuclear geometries in the vicinity of a conical intersection, the Born–Oppenheimer separatio