Optimal work extraction from quantum states by photo-assisted Cooper pair tunneling
| Autor: | Niels Lörch, Patrick P. Hofer, Nicolas Brunner, Christoph Bruder |
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| Rok vydání: | 2018 |
| Předmět: |
Superconductivity
Physics Josephson effect Quantum Physics Condensed Matter - Mesoscale and Nanoscale Physics Physics and Astronomy (miscellaneous) Materials Science (miscellaneous) FOS: Physical sciences ddc:500.2 7. Clean energy 01 natural sciences Atomic and Molecular Physics and Optics 010305 fluids & plasmas Fock space Quantum state Quantum mechanics Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences Electrical and Electronic Engineering Cooper pair Quantum Physics (quant-ph) 010306 general physics Quantum thermodynamics Quantum tunnelling Coherence (physics) |
| Zdroj: | Quantum Science and Technology, Vol. 3, No 3 (2018) P. 035014 |
| ISSN: | 2058-9565 |
| DOI: | 10.1088/2058-9565/aacbf3 |
| Popis: | The theory of quantum thermodynamics predicts fundamental bounds on work extraction from quantum states. As these bounds are derived in a very general and abstract setting, it is unclear how relevant they are in an experimental context, where control is typically limited. Here we address this question by showing that optimal work extraction is possible for a realistic engine. The latter consists of a superconducting circuit, where a LC-resonator is coupled to a Josephson junction. The oscillator state fuels the engine, providing energy absorbed by Cooper pairs, thus producing work in the form of an electrical current against an external voltage bias. We show that this machine can extract the maximal amount of work from all Gaussian and Fock states. Furthermore, we consider work extraction from a continuously stabilized oscillator state. In both scenarios, coherence between energy eigenstates is beneficial, increasing the power output of the machine. This is possible because the phase difference across the Josephson junction provides a phase reference. Published version |
| Databáze: | OpenAIRE |
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