The Gaussian entropy of fermionic systems
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...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
18 September 2012
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| In: |
Annals of physics
Year: 2012, Volume: 327, Issue: 12, Pages: 3138-3169 |
| DOI: | 10.1016/j.aop.2012.09.003 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1016/j.aop.2012.09.003 Verlag, Volltext: http://www.sciencedirect.com/science/article/pii/S0003491612001467 
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| Author Notes: | Tomislav Prokopec, Michael G. Schmidt, Jan Weenink |
| Summary: | 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 and classicalization. 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. |
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| Item Description: | Gesehen am 24.05.2018 |
| Physical Description: | Online Resource |
| DOI: | 10.1016/j.aop.2012.09.003 |