Landauer's Principle in a Quantum Szilard Engine without Maxwell's Demon.

Altug Sisman,Ronnie Kosloff,Alhun Aydin

doi:10.3390/e22030294

Altug Sisman, Ronnie Kosloff + Show 1 more

Open Access

https://doi.org/10.3390/e22030294

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Abstract

Quantum Szilard engine constitutes an adequate interplay of thermodynamics, information theory and quantum mechanics. Szilard engines are in general operated by a Maxwell’s Demon where Landauer’s principle resolves the apparent paradoxes. Here we propose a Szilard engine setup without featuring an explicit Maxwell’s demon. In a demonless Szilard engine, the acquisition of which-side information is not required, but the erasure and related heat dissipation still take place implicitly. We explore a quantum Szilard engine considering quantum size effects. We see that insertion of the partition does not localize the particle to one side, instead creating a superposition state of the particle being in both sides. To be able to extract work from the system, particle has to be localized at one side. The localization occurs as a result of quantum measurement on the particle, which shows the importance of the measurement process regardless of whether one uses the acquired information or not. In accordance with Landauer’s principle, localization by quantum measurement corresponds to a logically irreversible operation and for this reason it must be accompanied by the corresponding heat dissipation. This shows the validity of Landauer’s principle even in quantum Szilard engines without Maxwell’s demon.

Highlights

The second law of thermodynamics has been challenged by thought experiments many times.While the second law eludes itself from all charges so far, the interrogators have caused to reveal subtle links and features between different disciplines of physics
We have presented a quantum Szilard engine in the absence of a Maxwell’s demon
Maxwell’s demon and Szilard engine problems are used interchangeably in the literature because of the emphasis on erasure process, they can be considered to be separate in demonless quantum Szilard engine setups

Summary

Introduction

The second law of thermodynamics has been challenged by thought experiments many times. The major leap forward on the issue came in 1961 by Landauer who stated that any logically irreversible operation must be accompanied by some heat dissipation, which is called Landauer’s principle [6] In this context, Landauer gave an explicit example of resetting a memory to the reference state, which is presently known as information erasure. For the resolution of the classical versions of both Maxwell’s demon and Szilard engine paradoxes, it has been accepted by most that the demon must store the information about the molecule(s) and need to erase it to complete the cycle [9,10]. Localization by quantum measurement is a logically irreversible process and just like the information erasure, it must be accompanied by a corresponding heat dissipation.

A Szilard Engine without Maxwell’s Demon?

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Conclusions and Future Work