Ground state cooling of a radio-frequency LC circuit in an optoelectromechanical system

The paper “Ground state cooling of a radio-frequency LC circuit in an optoelectromechanical system” is available at Arxiv: arXiv:2009.00421.

Radio-frequency signals are used in a large variety of applications, and the possibility of operating them in a quantum regime with extremely low noise can be advantageous either for positioning, timing and sensing application, and for more fundamental science applications, such as the sensitive detection of rf signals of astrophysical nature. Quantum operation of rf circuits requires cooling them close to their quantum ground state, and here we show that this can be achieved by appropriately engineering the interactions in a hybrid tripartite optoelectromechanical system.

In detail we have developed a complete theory for laser cooling of a macroscopic radio-frequency LC electrical circuit by means of an optoelectromechanical system, consisting of an optical cavity dispersively coupled to a nanomechanical oscillator, which is in turn capacitively coupled to the LC circuit of interest. The driven optical cavity cools the mechanical resonator which in turn sympathetically cools the LC circuit. We determine the optimal parameter regime where the LC resonator can be cooled down to its quantum ground state, which requires a large optomechanical cooperativity, and a larger electromechanical cooperativity.