Feedback Levitation on an Inverted Potential: quantum systems optical trapping without heating with sensing applications

The control of levitated mesoscopic objects has developed into a flourishing field promising significant advances in sensing technologies, stochastic and quantum thermodynamics as well as macroscopic quantum physics. While optical levitation has already reached operation in the quantum regime, internal heating by absorption is a major challenge. With FLIP (Feedback Levitation on an Inverted Potential) we propose an original solution: dark field optical detection plus active feedback control provides position stabilization (without additional confining potential) and cooling to a close-to-pure quantum state without absorption. FLIP goes beyond the state of the art in several ways. It provides access to quantum control of absorbing objects in high vacuum (e.g. spin mechanics with NV-centers). It opens the door to large quantum superpositions via free-fall experiments with internally cold particles. It enables sensing and information thermodynamics with unstable potentials in the quantum regime. Following the recent demonstration of quantum limited position readout, real-time state reconstruction and feedback cooling to the ground state, it is the ideal time to develop levitation in the dark optical field. A controllable inverted potential for levitated particles is available in the host group, such that the project can be implemented from day zero and expanded towards a 3D dark quantum trap. Close collaboration with the Aspelmeyer group (partner group) and Prof. Kugi (ACIN) who jointly achieved feedback based ground state cooling will facilitate the implementation of FLIP. My expertise in FPGA-based optical feedback control puts me in a perfect position to implement FLIP. At the host group, I will expand my background in optomechanics, and quantum optics. Finally, continuing my research in information thermodynamics using FLIP, the proposed research will, if successful, sharpen my unique research profile and open fruitful research directions for my future career.