We realise a phase-sensitive closed-loop control scheme to engineer the fluctuations of the pump field which drives an optomechanical system, and show that the corresponding cooling dynamics can be significantly improved. In particular, operating in the counter-intuitive "anti-squashing" regime of positive feedback and increased field fluctuations, sideband cooling of a nanomechanical membrane within an optical cavity can be improved by 7.5~dB with respect to the case without feedback. Close to the quantum regime of reduced thermal noise, such feedback-controlled light would allow going well below the quantum backaction cooling limit.
@article{arxiv.1704.04556,
title = {Enhancing sideband cooling by feedback--controlled light},
author = {Massimiliano Rossi and Nenad Kralj and Stefano Zippilli and Riccardo Natali and Antonio Borrielli and Gregory Pandraud and Enrico Serra and Giovanni Di Giuseppe and David Vitali},
journal= {arXiv preprint arXiv:1704.04556},
year = {2017}
}