Le lundi 22 février à 15h30 à 15H30 en visioconférence : https://zoom.us/j/98609278424?pwd=Y2RIanJjY2gzWDNxQUVTNWh2ZU5JQT09

Optimization de membranes en nitrure de silicium pour des circuits mécaniques-supraconducteurs hybrides

In this thesis, we study an engineered mechanical oscillator coupled to a microwave cavity. In a preliminary experiment, microwave photons were used as a cold bath to reduce the temperature of the mechanical oscillator by a factor 500. We present several improvements to the membranes which should enable us to cool them down to their quantum ground state. In particular, we explore the rich physics of phononic bangaps to isolate an ultrahigh-quality-factor membrane mode from decoherence channels, a technique known as « soft-clamping ». We discuss the perspectives of preparing nonclassical states of motion by exploiting superconducting qubits as a nonlinear resource.