| Abstract: | The thermodynamic implications of information processing have recently received renewed attention, in contexts such as quantum information theory, the synthesis of artificial molecular machines, and feedback control in microscopic systems. A question at the heart of this field is whether or not the Shannon entropy of a random string of data ought to be treated as a genuine thermodynamic entropy, with consequences for the conversion of heat into work. I will address this issue by describing a model system that operates as an autonomous Maxwell Demon. This "demon" interacts with a thermal reservoir, a stream of bits, and a mass that can be lifted or lowered. Its dynamics are modeled with thermodynamically consistent transition rates. The steady-state behavior of the model can be solved exactly, and this solution is used to construct the nonequilibrium phase diagram as a function of the model parameters. The demon can act either as an engine, converting heat to work (lifting the mass) while writing information to the stream of bits; or as an eraser, using the energy of the falling mass to erase information in the bit stream. The model offers a simple paradigm for exploring the interplay between heat, work and information in small systems. |
