  Simultaneously cooling the rotational and translational motion of nanoscale
dielectrics into the quantum regime is an open task of great importance for
sensing applications and quantum superposition tests. Here, we show that the
six-dimensional ground state can be reached by coherent-scattering cooling with
an elliptically polarized and shaped optical tweezer. We determine the cooling
rates and steady-state occupations in a realistic setup and discuss
applications for mechanical sensing and fundamental experiments.
