Demons at Work

A Maximum Work Theorem for Maxwell's Demons

Henrik Sandberg, Jean-Charles Delvenne, Nigel J. Newton, and Sanjoy K. Mitter Automatic Control Lab, KTH Royal Institute of Technology, Stockholm, Sweden ICTEAM and CORE, Université catholique de Louvain, Louvain-la-Neuve, Belgium School of Computer Science and Electronic Engineering, University of Essex, Colchester, UK Laboratory for Information and Decision Systems, MIT, Cambridge, Massachuse...

Maximum work extraction and implementation costs for nonequilibrium Maxwell's demons.

We determine the maximum amount of work extractable in finite time by a demon performing continuous measurements on a quadratic Hamiltonian system subjected to thermal fluctuations, in terms of the information extracted from the system. The maximum work demon is found to apply a high-gain continuous feedback involving a Kalman-Bucy estimate of the system state and operates in nonequilibrium. A ...

On Demons and Oracles

Implementing Demons and Ratchets

Experimental results show that ratchets may be implemented in semiconductor and chemical systems, bypassing the second law and opening up huge gains in energy production. This paper summarizes or describes experiments and results on systems that effect demons and ratchets operating in chemical or electrical domains. One creates temperature differences that can be harvested by a heat engine. A s...

Demons in Physics

Maxwell’s ”finite being” was born in 1867, as one ”who knows the paths and velocities of all the molecules” ([7], p.213), and who, unlike us, is ”clever enough” ([7], p.213), and can violate the second law of thermodynamics. It was baptized as a demon by Lord Kelvin ([7], p. 214), and ever since has fueled the discussions in the foundations of statistical mechanics. Since its inception, and con...