Electron beam to light and light to electron beam: Come play with me!

This is a transcript of the presentation given at the symposium celebrating Swapan Chattopadhyay’s retirement held via Zoom on April 30, 2021. Beginning with a demonstration of the Maxwell’s demon paradox, I show its similarity to Simon van der Meer’s stochastic cooling method and briefly follow the evolution of ideas for demon exorcism. I review Rolf Landauer’s principle governing the thermodynamics of information and its refinement by Charles Bennett widely used to vindicate the second law of thermodynamics. After that, I present the idea for a stochastic cooling of electrons and positrons without the amplifier and without the need to gather, process and act on the information about the system by the external observer. Finally, I show that quantum mechanics plays an essential role in this cooling process and thus keeps the Maxwell’s demon at bay. I was inspired to come up with this story by Swapan Chattopadhyay, who suggested the title for my presentation.