Invited
Remote Quantum Entanglement between Two Micromechanical Oscillators

We would like to discuss recent experiments where we demonstrate various non-classical mechanical states by coupling an engineered mechanical oscillator to single optical photons. Mechanical systems have recently attracted a lot of attention for their potential usage in quantum information processing tasks, for example as compact quantum memories or as transducers between different types of quantum systems. 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 resonances in the conventional telecom band. We discuss recent results establishing 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 tasks.