Título: Quantum experiments with massive, mechanical oscillators

Abstract: Mechanical systems have recently attracted significant attention for their potential use in quantum information processing tasks, for example as compact quantum memories or as transducers between different types of quantum systems. Early experiments included ground-state cooling of the mechanical motion and squeezing of the optical field. Recent advances have allowed to perform measurements which realize various mechanical quantum states.

Here, we would like to discuss several experiments where we demonstrate such non-classical mechanical states by coupling an engineered mechanical oscillator to single optical photons. Our approach is based on so-called nanobeam optomechanical crystals, which possess engineered mechanical resonances in the Gigahertz regime that can be addressed optically from the conventional telecom band. These experiments establish quantum control over such devices, including the heralded generation and on-demand readout of single phononic excitations. We furthermore demonstrate high quality light-matter entanglement as well as heralded entanglement between two mechanical modes employing quantum optics protocols. These results are a promising step towards the usage of such devices for quantum information processing tasks and testing quantum physics with massive objects.