Testing quantum mechanics and gravity with levitated optomechanics

We will report on recent progress in levitated optomechanics experiments in order to test the quantum superposition principle as well as the interplay between quantum mechanics and gravity. The mass of nanoparticles is large compared to the mass of single atoms and experiments manipulating such particles in vacuum are promising to test both theories in a new parameter regime. The mass of these particles is small enough so that the generation of non-classical centre of mass motional states, such as spatial superposition states, is not impossible - but at the same time the mass is large enough so that the effects of gravity become significant for the dynamics of those non-classical states. This represents a new paradigm to test quantum mechanics and gravity in the low energy - non-relativistic regime. We will discuss recent proposals for concrete expriments as well as report on their feasiblty based on experimental state of the art.