Ring structural transions in strongly coupled dusty plasmas

In dusty plasmas, a structural transition may occur due to a variation of the coupling strength between dust particles and/or due to an external applied field. Here, we examine how a strongly coupled dusty plasma can be transformed from a circular monolayer structure (a collection of rings with different diameters nested within the same plane) to a cylindrical surface structure (a collection rings with same diameters aligned in parallel planes) and vice-versa. This transformation has been observed numerically under the varying strength of an external applied circular potential with a central barrier, i.e., a "Mexican hat" potential. The transition of the trapped dust particles from a monolayer to a cylindrical surface is found proportional to the strength of the applied potential. For a fixed number of particles, we have also observed smaller number of rings in the cylindrical structure than the monolayer. To observe this structural transition molecular dynamics simulations have been performed where dust particles interact through Yukawa potential.