At room temperature, quantum optomechanical phenomena have only been observed in pioneering experiments where an optical restoring force controls the oscillator stiffness, akin to the vibrational motion of atoms in an optical lattice. These include both levitated nanoparticles and optically-trapped cantilevers. Recent advances in engineered mechanical resonators, where the restoring force is provided by material rigidity rather than an external optical potential, have realized ultra-high quality factors (Q) by exploiting`soft clamping’, achieving more than 100 quantum coherent oscillations at room temperature. In this talk, I will explain our recent advances of reaching the quantum regime of cavity optomechanics at room temperature using engineered mechanical resonators, and discuss various dominant physical processes that emerge in this parameter regime.

Guanhao Huang received B.S. degree in physics (2018) from Tsinghua University, where he worked on realizing programmable boson sampling gates in trapped ion systems. He is currently a physics PhD student in the laboratory of photonics and quantum measurements at EPFL, working on room temperature quantum optomechanics using engineered mechanical resonators, and free-electron couplings to integrated photonic circuits.