The Gaussian entropy of fermionic systems
Autor: | Prokopec, Tomislav, Schmidt, Michael G., Weenink, Jan |
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Rok vydání: | 2012 |
Předmět: | |
Zdroj: | Annals Phys. 327, 3138 (2012) |
Druh dokumentu: | Working Paper |
DOI: | 10.1016/j.aop.2012.09.003 |
Popis: | We consider the entropy and decoherence in fermionic quantum systems. By making a Gaussian Ansatz for the density operator of a collection of fermions we study statistical 2-point correlators and express the entropy of a system fermion in terms of these correlators. In a simple case when a set of N thermalised environmental fermionic oscillators interacts bi-linearly with the system fermion we can study its time dependent entropy, which also represents a quantitative measure for decoherence. We then consider a relativistic fermionic quantum field theory and take a mass mixing term as a simple model for the Yukawa interaction. It turns out that even in this Gaussian approximation, the fermionic system decoheres quite effectively, such that in a large coupling and high temperature regime the system field approaches the temperature of the environmental fields. Comment: 28 pages, 13 figures, updated to match published version |
Databáze: | arXiv |
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