Speaker
Description
Quantum feedback is a powerful technique for controlling quantum systems. The conventional strategy relies on quantum-limited measurements followed by classical processing and feedback actuation onto the system. However, quantum mechanics also allows coherent feedback of quantum signals. Such coherent feedback may exploit the information stored in non-commuting observables, while circumventing the decoherence and backaction noise associated with a measurement. Coherent feedback has thus the potential to improve quantum control and provide new capabilities in a broad range of physical systems. We experimentally demonstrate coherent feedback control of a mechanical oscillator with a quality factor of 46 million. Using this scheme, we demonstrate cooling of the mechanical oscillator's motion to its quantum ground state.