Electrical Maxwell Demon and Szilard Engine Utilizing Johnson Noise, Measurement, Logic and Control

Laszlo Bela Kish,Claes-Göran Granqvist,Dante R Chialvo

doi:10.1371/journal.pone.0046800

Abstract

We introduce a purely electrical version of Maxwell's demon which does not involve mechanically moving parts such as trapdoors, etc. It consists of a capacitor, resistors, amplifiers, logic circuitry and electronically controlled switches and uses thermal noise in resistors (Johnson noise) to pump heat. The only types of energy of importance in this demon are electrical energy and heat. We also demonstrate an entirely electrical version of Szilard's engine, i.e., an information-controlled device that can produce work by employing thermal fluctuations. The only moving part is a piston that executes work, and the engine has purely electronic controls and it is free of the major weakness of the original Szilard engine in not requiring removal and repositioning the piston at the end of the cycle. For both devices, the energy dissipation in the memory and other binary informatics components are insignificant compared to the exponentially large energy dissipation in the analog part responsible for creating new information by measurement and decision. This result contradicts the view that the energy dissipation in the memory during erasure is the most essential dissipation process in a demon. Nevertheless the dissipation in the memory and information processing parts is sufficient to secure the Second Law of Thermodynamics.

Highlights

Heat engines [1] utilize temperature differences to produce work while ‘‘heat demons’’ [2,3,4,5,6,7,8] employ information about instantaneous amplitudes of thermal fluctuations and execute control to produce a temperature difference and/or work
There is an old debate [8,9,10,11,12,13,14,19,20,21] on the question whether the energy dissipation due to erasure of information in the memory is the fundamental process to save the Second Law of Thermodynamics or if the generation of new information via measurement and decision [2,13] and control requirements [9] is more important
The electrical Maxwell demon described below employs the Johnson noise of resistors as well as measurement, decision, logic operations and control for pumping heat

Summary

Introduction

Heat engines [1] utilize temperature differences to produce work while ‘‘heat demons’’ [2,3,4,5,6,7,8] employ information about instantaneous amplitudes of thermal fluctuations and execute control to produce a temperature difference and/or work. The electrical Maxwell demon described below employs the Johnson noise of resistors as well as measurement, decision, logic operations and control for pumping heat.

Results

Conclusion