Saturday, 22 June 2019

thermodynamics - Non-extensivity in a few body system


Thermodynamics finds application in many areas of physics, many of them sharing the feature of fluid-like or many-body like behavior.


However, small systems or few body systems have been studied too using thermodynamics. But generally it is accepted that these systems behave differently from macroscopic systems: they are non-extensive.


Non-extensivity generally is deduced from the fact that extensive properties in these systems don't add up the way they would in macroscopic ones. But I am struggling to find hard evidence of this, because merging two systems, at least in a thermodynamics view, implies that we should check the equilibrium cases only.


I mean, when I say that for two non extensive systems with entropies $S_a$ and $S_b$ it doesn't hold $S_a + S_b = S_{a+b}$, I should be checking that all these systems are under the same conditions regarding intensive properties, right? If not, then not even macroscopic systems would exhibit extensivity.


My question is: Are there publications checking this aspects for certain small systems?


I am searching for a papers where this is checked, because I have not seen this done and find it strange.




Answer



A recent work that uses nanothermodynamics and includes a computational investigation of the kind you are asking about for an Ising lattice:


R.V. Chamberlin, The Big World of Nanothermodynamics


Sec.5 of the following paper makes a reference to another paper that appears to have tested the limits of usual thermodynamics in single polymer stretching experiments:


J. M. Rubi, D. Bedeaux, and S. Kjelstrup, Thermodynamics for Single-Molecule Stretching Experiments, J. Phys. Chem. B 2006, 110, 12733-12737


You may also find some clues in discussion and refs from Secs. 2.3-2.5 of this paper:


T. Dauxois, S. Ruffo, E. Arimondo, M. Wilkens, Dynamics and Thermodynamics of Systems with Long-Range Interactions: An Introduction


It is actually the Intro to this volume: Dynamics and Thermodynamics of Systems with Long Range Interactions, Eds. T. Dauxois, S. Ruffo, E. Arimondo, M. Wilkens (Google Books)


No comments:

Post a Comment

Understanding Stagnation point in pitot fluid

What is stagnation point in fluid mechanics. At the open end of the pitot tube the velocity of the fluid becomes zero.But that should result...