Octupolar metal nanoparticles as optically driven, coherently controlled nanorotors

We predict theoretically that nanoparticles of octupolar symmetry (nanotriangles and nanotetrahedra) subjected to a coherent mixture of fundamental and second harmonic fields will rotate and orient controlled by the relative phase between these fields. This effect is described quantitatively for triangular and tetrahedral clusters of metal nanospheres where it can be observed experimentally and used in applications.