Directional bond breaking of CO molecules by counter-rotating circularly polarized two-color laser fields

We experimentally studied the dissociative single and double ionization of CO molecules by counter-rotating circularly polarized two-color (CRTC) laser fields. By coincidently measuring the electrons and the fragmented ions, trefoil asymmetric momentum distributions of C⁺ in the polarization plane were observed, which are mainly determined by the selective ionization of CO with asymmetric orbitals. The threefold pattern could rotate continuously in the two-dimensional space by finely tuning the relative phase of the CRTC fields, providing a new method to manipulate the directional bond breaking of molecules by strong laser fields.