MPL Theory Seminars: Prof. Alexia Auffèves

29.09.2015, 16:00

Reversible work extraction in a hybrid opto-mechanical system

With the progress of nano-technology, thermodynamics also has to be scaled down, calling for specific protocols to extract and measure work. Usually, such protocols involve the action of an external, classical field (the battery) of infinite energy, that controls the energy levels of a small quantum system (the calorific fluid). Here we suggest a realistic device to reversibly extract work in a battery of finite energy : a hybrid optomechanical system (Fig.1). Such devices consist of an optically active two-level quantum system interacting strongly with a nano-mechanical oscillator that provides and stores mechanical work, playing the role of the battery. We identify protocols where the battery exchanges large, measurable amounts of work with the quantum emitter without getting entangled with it. When the quantum emitter is coupled to a thermal bath, we show that thermodynamic reversibility is attainable with state-of-the-art devices, paving the road towards the realization of a full cycle of information-to- energy conversion at the single bit level [1]. Perspectives opened by hybrid opto-mechanical systems in the field of quantum thermodynamics will be discussed. [1] C. Elouard, M. Richard, A. Auffèves, Reversible work extraction in a hybrid optomechanical system, New Journal of Physics 17, 055018 (2015) (Special focus on Quantum Thermodynamics).[2] M. Richard and A. Auffèves, Optical driving of macroscopics mechanical motion by a single two-level system, Physical Review A 90, 023818 (2014).[3] C. Elouard and A. Auffèves, A quantum system strongly coupled to a finite size reservoir: The case of a hybrid optomechanical system, In preparation.


Time: Tuesday, Semptember 19th 2015 at 16:00

Place: Günther-Scharowsky-Str. 1/Bldg. 24, 91058 Erlangen, Seminar room 435