Helicity in cylindrically confined Yukawa systems

By lattice sum minimization, we predict the ground state of particles interacting via a Yukawa potential which are confined in a quasi–one-dimensional cylindrical tube. As a function of screening strength and particle density, the zero-temperature phase diagram exhibits a cascade of stable crystals with both helical and non-helical structures. These quasi–one-dimensional crystals can be confirmed in experiments on confined charged colloidal suspensions, trapped dusty plasmas or ions in nanotubes