Towards Strain-Coupled Optomechancics with Rare-Earth Doped Crystals

Signe Seidelen
June 20th, 2019 SIGNE SEIDELIN Institut NEEL, CNRS
Université Grenoble Alpes

A challenge of modern physics is to investigate the quantum behavior of a bulk material object - for instance a mechanical oscillator - placed in a non-classical state. One major difficulty relies in interacting with the mechanical object without perturbing with its quantum behavior. An approach consists of exploiting a hybrid quantum system consisting of a mechanical oscillator coupled to an atom-like object, and interact via the atom-like object. A particularly appealing coupling mechanism between resonator and “atom” is based on material strain. Here, the oscillator is a bulk object containing an embedded artificial atom (dopant, quantum dot, ...) which is sensitive to mechanical strain of the surrounding material. Vibrations of the oscillator result in a time-varying strain field that modulates the energy levels of the embedded structure. We have suggested to use rare-earth doped crystals for strain-coupled systems and proposed a mechanism to cool down the resonator. More concretely, we are currently studying an yttrium silicate (Y2SiO5) crystal containing a triply charged europium ion (Eu3+), which is optically active. The reason behind this choice stems from the extraordinary coherence properties of this dopant, combined with its high strain-sensitivity: the Eu3+ in an Y2SiO5 matrix has an optical transition with the narrowest linewidth known for a solid-state emitter, and the transition is directly sensitive to strain. We have succesfully fabricated mechanical resonators, designed and set up the experiment, and achieved a signal-to-noise ratio compatible with the planned measurements, as well as measured the strain sensitivity of europium ions in bulk Y2SiO5 crystals.

Seminar, June 2’, 2019, 12:00. ICFO’s Seminar Room

Hosted by Prof. Frank Koppens