Unitary work extraction from a generalized Gibbs ensemble using Bragg scattering
| Autor: | Wouter Verstraelen, Michiel Wouters, Dries Sels |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Statistical ensemble
Canonical ensemble Physics Quantum Physics Statistical Mechanics (cond-mat.stat-mech) Entropy production Bragg's law FOS: Physical sciences 02 engineering and technology Fermion 021001 nanoscience & nanotechnology 01 natural sciences Quantum Gases (cond-mat.quant-gas) Quantum mechanics 0103 physical sciences Thermodynamic limit 010306 general physics 0210 nano-technology Adiabatic process Condensed Matter - Quantum Gases Quantum Physics (quant-ph) Circular ensemble Condensed Matter - Statistical Mechanics |
| Zdroj: | Phys. Rev. A |
| ISSN: | 2469-9926 |
| Popis: | We investigate work extraction from integrable quantum systems under unitary operations. As a model system, we consider noninteracting fermions in one dimension. Thanks to its integrability, this system does not thermalize after a perturbation, even though it does reach a steady state which can be described by a generalized Gibbs ensemble (GGE). Such a GGE has an excess free energy compared to a thermal state and we propose to extract this energy by applying Bragg pulses. We show how all the available work in the GGE can be extracted in the adiabatic limit while some excess energy is left at finite times. The unextracted work reaches the adiabatic limit as a power law with exponent $z=\ensuremath{-}2$ for small systems and with $z=\ensuremath{-}1$ in the thermodynamic limit. Two distinct protocols for combining the Bragg operations are compared, and in some systems an extensive difference in efficiency arises. From the unextracted work and the entropy production, a notion of temperature is defined and compared to the Boltzmann-Gibbs temperature of the system. |
| Databáze: | OpenAIRE |
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