Erlangen 2022 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
Q: Fachverband Quantenoptik und Photonik
Q 65: Quantum Information (Miscellaneous)
Q 65.7: Talk
Friday, March 18, 2022, 12:00–12:15, Q-H12
Incompatibility of energy conservation and fluctuation theorems for quantum work — •Karen Hovhannisyan1 and Alberto Imparato2 — 1University of Potsdam, Institute of Physics and Astronomy, 14476 Potsdam, Germany — 2Aarhus University, Department of Physics and Astronomy, Ny Munkegade 120, 8000 Aarhus, Denmark
Characterizing the fluctuations of work in coherent quantum systems is a notoriously elusive problem. Aiming to reveal the ultimate source of this elusiveness, we demand of a work measurement the sheer minimum and check if those demands can be met at all. We require (A) energy conservation for arbitrary initial states of the system and (B) the Jarzynski equality for thermal initial states. By energy conservation we mean that the average work must be equal to the difference of initial and final average energies, and that untouched systems must exchange deterministically zero work. Requirement B encapsulates the second law of thermodynamics and the quantum–classical correspondence principle. We prove that work measurement schemes that do not depend on the system’s initial state satisfy B if and only if they coincide with the famous two-point measurement scheme, thereby establishing that state-independent schemes cannot simultaneously satisfy A and B. Expanding the scope to the realm of state-dependent schemes allows for more compatibility between A and B. However, merely requiring the state-dependence to be continuous still effectively excludes the possibility of coexistence of A and B.