Crystalline oxide coatings for gravitation wave mirrors

The main goal of the PhD project is to develop novel crystalline oxide thin films on silicon and on sapphire for gravitational wave (GW) mirror applications. One of the main limiting factors in (GW) research is related to the Brownian motion noise of the current amorphous mirror coatings. This noise originates from the mechanical properties of the coatings and in particular of the mechanical losses. Single crystals films should have much lower mechanical losses and better specifications that can match those necessary for future GW telescopes such as the Einstein Telescope. A significant part of the research will be to grow high quality crystalline oxide thin films with various deposition techniques (molecular beam epitaxy, chemical vapour deposition, etc.) as well as their detailled structural and microscopic characterisation with scanning transmission electron microscopy (S)TEM using the advanced facilities in the laboratories. In addition, the mechanical and optical properties of the coatings will be measured as a function of temperature. Numerical modelling to understand the observed structures and responses will provide physical insight and will be performed where necessary.