Środowiskowe Seminarium z Informacji i Technologii Kwantowych

We propose and demonstrate a simple feedback control mechanism for the squeezing of a quantum harmonic oscillator embodied by the phononic mode of a mechanical oscillator. Our proposal is based on frequent re- peated measurements and re-initialisation of the state of a two-level system ancilla that interacts with the os- cillator. We demonstrate that the steady-state of the mechanical mode can be significantly squeezed with such a simple, non-adaptive feedback loop, which offers interesting possibilities for quantum state engineering and feedback-based state steering in an explicitly open-system scenario.