Quantum Feedback Thermal Machines An IQS Seminar Series Technical Talk by Bibek Bhandari
September 12, 2022
Wednesday, 14 September 2022 @ 10 AM in 149 Keck Center, or join us on Zoom.
Abstract: We will discuss the thermodynamic aspects of a single qubit-based and coupled qubit-based devices, powered by weak quantum measurements, and feedback controlled by a quantum Maxwell’s demon. Single qubit-based device: We will discuss both discrete and time-continuous operation of the measurement-based device at finite temperature of the reservoir. In the discrete example where a demon acquires information via discrete weak measurements, we will show that the thermodynamic variables including the heat exchanged, extractable work, and the entropy produced are completely determined by an information theoretic measure of the demon’s perceived arrow of time. In the time-continuous limit, we will present the exact finite-time statistics of work, heat and entropy changes along individual quantum trajectories of the quantum measurement process and relate them to the demon’s arrow of time. Coupled qubit-based devices: we will study the discrete case for the coupled qubit-based system and study the relation between thermodynamic quantities and the arrow of time. We will also present the case for obtaining feedback based quantum thermal machines when the reservoirs are not detachable. Finally, we will give a brief outline for future directions we are pursuing.