Collision states and scar effects in charged three-body problems

Semiclassical methods form a bridge between classical systems and their quantum counterparts. An interesting phenomenon discovered in this connection is the scar effect, whereby energy eigenstates display enhancement structures resembling the path of unstable periodic orbits. This paper deals with collision states in charged three-body problems, in periodic media, which are scarred by unstable classical orbits. The scar effect has a potential for practical applications because orbits corresponding to zero measure classical configurations may be reached and stabilized by resonant excitation. It may be used, for example, to induce reactions that are favoured by unstable configurations.