Emergence of Synchronization-Induced Patterns in Two-dimensional Magnetic Rod Systems under Rotating Magnetic Fields

We investigate the dynamics of two-dimensional assemblies of rod-shaped magnetic colloids under the influence of an external rotating magnetic field. Using molecular dynamics, we simulate the formation of patterns that emerge based on the synchronization degree between the magnetic rods and the rotating field. We then explore the structural and dynamic characteristics of the resulting steady states, examining their evolution as a function of changes in the rods' aspect ratio, the strength of the external magnetic field, and its rotation frequency. Three distinct synchronization regimes of the rods with the magnetic field are clearly observed. A detailed set of phase diagrams illustrates the complex relationship between the magnitude of the external magnetic field and its rotation frequency and how these parameters govern the formation of unique self-organized structures.